Bolstering the Quad: The case for a collective approach to maritime security

Executive summary

Key judgements

• Although the Quad has emerged as a bulwark of a free, open and resilient Indo-Pacific and a leading provider of public goods, it is not living up to its potential as a contributor to regional security and defence in the maritime domain.
• This is a problem for Indo-Pacific security. Given its member states’ collective military heft and stated interest in upholding a favourable balance of power in the region, the Quad has a vital role to play in preserving stability and deterring major power aggression.
• Today, this is needed more than ever as China’s growing military capabilities and coercive statecraft challenge the foundations of regional order from the Himalayas and the Indian Ocean to Northeast Asia, the South China Sea, and the South Pacific.
• While Quad countries have pursued an array of defence agreements, military exercises, and maritime security initiatives at the “Quad-minus” level, these are not comprehensive, nor have they been networked and standardised in ways that facilitate effective operational collaboration between all four members.
• The main reason for this is that a set of political sensitivities and geostrategic concerns has prevented Quad countries from embracing this kind of collective security agenda.
• But these constraints are beginning to lessen as the Quad steps up its mission to deliver collective public goods, and as its members come to recognise China as a common military challenge that requires a degree of collective action and security coordination to address.
• This does not mean the Quad can or should pursue a formal collective defence framework. But it does mean Quad countries should be able to better leverage and network their respective capabilities to advance a collective approach to defence cooperation on key maritime security tasks of mutual interest and significant value to the region.
• The Quad should capitalise on this diplomatic opportunity and geostrategic imperative to pursue a collective maritime security strategy across five high-priority areas: maritime domain awareness; anti-submarine warfare; maritime logistics; defence industrial and technological cooperation; and maritime capacity building.

US President Joe Biden, Australian Prime Minister Anthony Albanese, Japanese Prime Minister Fumio Kishida and Indian Prime Minister Narendra Modi hold a Quad meeting on the sidelines of the G7 Leaders’ Summit in Hiroshima, 20 May 2023Source: Getty

Recommendations

This report lays out a case and provides a menu of policy options for how the Quad can pursue a collective approach to Indo-Pacific maritime security, with a particular focus on regional deterrence and defence.

On collective maritime domain awareness, the Quad should:

• Develop a more networked and persistent maritime domain awareness (MDA) capability as a foundation for tracking activities of interest across geographic areas of responsibility, including as a baseline for potential coordinated efforts to build a comprehensive, real-time picture of Chinese military movements.
• Discuss the limitations of existing tactical data link arrangements within the Quad, and work towards an interface protocol to govern information-sharing between all Quad partners, with particular attention paid to a commonality of hardware and software or, at the least, interoperability of different tools.
• Update bilateral information security agreements and pursue a multi-party agreement to enable Quad countries to develop a more holistic operating picture of activities of interest across the Indo-Pacific.
• Selectively integrate Quad countries’ coastal facilities, island territories and regional access locations to conduct more persistent and coordinated MDA operations; and jointly assess the requirements of hosting and replenishing one another’s MDA assets like maritime patrol aircraft.
• Set up MDA and intelligence, surveillance and reconnaissance (ISR) initiatives that combine shared access, information-sharing and analysis, and platform interoperability to create a common operating picture within geographically defined Quad groupings.

On coordinated anti-submarine warfare operations, the Quad should:

• Build collective anti-submarine warfare (ASW) capability by developing higher levels of interoperability and more persistent patterns of unscripted cooperation to include tracking and “handing off” overwatch responsibility for Chinese submarines transiting geographic areas of responsibility.
• Develop mechanisms to conduct joint assessments of underwater domain awareness (UDA) data gathered by national sensors, towed acoustic arrays, ASW aircraft and unmanned vehicles, focusing on agreed-upon areas of operation with an eye towards joint collection in the future.
• Establish service- or bureaucratic-level mechanisms for conducting four-way combined assessments of underwater domain information from select areas, and work towards a formal classified sharing network for the development and dissemination of key submarine-related intelligence.
• Identify the necessary upgrades to existing bilateral agreements and access locations required to support more frequent coordinated aerial ASW activities.

On integrated maritime logistics, the Quad should:

• Develop the collective capacity to seamlessly refuel, resupply and repair maritime assets from any member on short notice, and formally commit to this agenda at the political and operational levels.
• Establish a Quad Logistics Coordination Cell within the US Navy’s Commander, Logistics Group Western Pacific that incorporates all four partners and performs logistics planning for the Indian and Pacific Oceans, using combined maintenance and resupply capabilities on a regular basis.
• Elevate maritime logistics discussions to the Quad Maritime Security Working Group to promote information-sharing on bilateral and trilateral logistics activities, pursue opportunities for aligning or networking concurrent activities, and develop options for Quad logistics planning, exercises and operations.
• Conduct a Quad-wide equipment interoperability review to ensure logistics compatibility and procedural standardisation, and support this with a framework and requirement for placing Quad liaisons on one another’s logistics vessels to encourage familiarity and exchange best practices.

On defence industrial and technology cooperation, the Quad should:

• Establish a Quad Initiative for Maritime Security Capabilities within the existing Maritime Security Working Group to assess individual and collective maritime defence requirements, identify opportunities for and barriers to collaboration, and advance cooperation on interoperable maritime capabilities.
• Launch a defence supply chain mapping project with an initial focus on critical lethal and non-lethal items, like sonobuoys and long-range anti-ship missiles, used across common platforms such as the P-8 maritime patrol aircraft.
• Explore collective supply chain innovations for in-demand capabilities by emulating the Quad Vaccine Initiative model, including its joint financing and distributed production arrangements.
• Establish formal training programs and embed arrangements to train Quad officials and industry representatives on one another’s defence procurement systems and processes, building on the model being developed by Japan’s Acquisition, Technology and Logistics Agency (ATLA) for Indian counterparts.

On coordinated maritime capacity building, the Quad should:

• Establish a Maritime Capacity Building Initiative (MCBI) to expand Quad efforts to strengthen the maritime security capabilities of key Southeast Asian partners and operate as a “clearing house” to align efforts, share information and eliminate duplicative programs.
• Co-design and co-administer coast guard training programs for Southeast Asian partners, with a view to establishing a Quad Coast Guard Working Group.
• Set up an integrated working group within the MCBI to identify opportunities for Quad countries to provide complimentary platforms to Southeast Asian partners, with a focus on MDA, ISR, and patrol assets.
• Scope options to collectively provide joint force integration assistance programs that support Southeast Asian nations to achieve higher levels of interoperability between their legacy, often Russian-sourced forces, and newly-acquired Western capabilities from multiple suppliers.
• Undertake a pilot program to collectively refurbish existing Quad capabilities for transfer to Southeast Asian partners.

Introduction

The Quad has emerged as one of the Indo-Pacific’s premier minilateral forums and a bulwark of a free, open and resilient region. Ever since Australia, India, Japan and the United States restarted the grouping in 2017, its achievements have been swift and far-reaching. The Quad now encompasses an annual leaders’ summit and foreign ministers’ meeting. It has established working groups to deliver practical “public goods” for regional countries in areas ranging from global health and critical technologies to climate, infrastructure and space. And it has gone out of its way to foster new “habits of cooperation” among its four members and other Indo-Pacific partners in support of a more peaceful, stable and prosperous region.¹

But the Quad is not living up to its potential as a contributor to regional security and defence in the maritime domain. Although the grouping has made substantial investments in non-traditional maritime security, like humanitarian assistance and disaster relief, and is delivering valuable public goods through the 2022 Indo-Pacific Maritime Domain Awareness initiative, its quadrilateral efforts have not prioritised coordination on issues relating to traditional deterrence and defence. The situation is very different at the Quad-minus level, where members have pursued a vast array of agreements and maritime security initiatives to deepen operational cooperation in areas like maritime domain awareness, anti-submarine warfare and logistics support. These, in effect, represent the bilateral building blocks of what could become a Quad-wide approach to collective maritime security. At present, however, these Quad-minus arrangements are neither comprehensive nor have they been sufficiently networked and standardised to facilitate effective defence collaboration between all four Quad countries. When it comes to high-end maritime security and defence cooperation, the Quad is still less than the sum of its parts.

When it comes to high-end maritime security and defence cooperation, the Quad is still less than the sum of its parts.

This is a serious problem for Indo-Pacific security. Given its members’ collective military heft and stated interest in upholding a favourable balance of power in the region, the Quad has a potentially vital role to play in preserving stability and deterring major power aggression. Today this is needed more than ever as China’s growing military capabilities and coercive statecraft is challenging the foundations of regional order from the Himalayas and the Indian Ocean to Northeast Asia, the South China Sea and the South Pacific. These developments, to be sure, are not lost on individual Quad countries. All four have recently come to recognise China as a common military challenge that is better addressed through collective action and security coordination, especially in areas where Beijing is seeking to coerce others on territorial disputes. All are in the midst of major defence build-ups designed to improve their national capacity to deter and defend against China’s rising power, spurred on by an uptick in Chinese assertiveness in places like the Sino-Indian border and the East and South China Seas. And all are pursuing a growing schedule of defence cooperation with like-minded regional partners as a way of bolstering their ability to shape and defend the deteriorating strategic environment. Better aligning these efforts within the Quad to ensure its members have a common capacity to operate together in support of shared deterrence and defence objectives would make an invaluable contribution to Indo-Pacific stability and maritime security.

US Secretary of State Antony Blinken, Japanese Foreign Minister Yoshimasa Hayashi, Australian Foreign Minister Penny Wong and Indian Foreign Minister Subrahmanyam Jaishankar participate in a Quad Ministers panel in New Delhi, 3 March 2023Source: Getty

There are longstanding reasons why this has not happened. A set of political sensitivities and geostrategic concerns has prevented the four countries from embracing a Quad-wide defence agenda. These include differently weighted strategic priorities, India’s place outside the US alliance network, anxiety about losing regional support for the Quad, concerns about diluting the Quad’s public goods agenda, and a lack of bureaucratic capacity and domestic support. Yet, many of these constraints are beginning to lessen as the Quad steps up its overall mission to deliver collective public goods to the region and as the collective demands of strategic competition with China become more apparent to its members. This does not mean the Quad is able to embrace an explicit collective defence framework within the grouping, which, in any case, would almost certainly be counterproductive for its wider regional order agenda at this time. But it does mean that Quad countries should now be in a position to better manage existing constraints and leverage their collective capabilities to advance a Quad-wide approach to defence cooperation on key maritime security tasks of mutual interest and value to the region.

This report lays out a case for how the Quad can pursue this kind of collective approach to Indo-Pacific maritime security, with a particular focus on regional deterrence and defence. Departing from the premise that there is a geostrategic imperative and diplomatic opportunity to galvanise Quad countries into action on this front, we argue the Quad can — and should — strengthen its existing network of cross-bracing defence agreements and maritime security arrangements to facilitate deeper operational collaboration across the Indo-Pacific. Specifically, we outline five high-value and achievable tasks that the Quad should prioritise as part of this agenda. These are:

Collective maritime domain awareness;

1. Coordinated anti-submarine warfare operations;
2. Integrated maritime logistics;
3. Defence industrial and technological cooperation; and
4. Coordinated maritime capacity building.

For each of these, we also set out detailed policy recommendations for decision-makers to consider as part of implementing particular aspects of this approach. Above all, we argue that by making a deliberate effort to consolidate, standardise and expand Quad-wide efforts in each of these areas, Australia, India, Japan and the United States could bolster their independent and collective capacity to strengthen maritime security and promote regional stability.

Pedestrians walk past a big screen displaying news about the Quad Leaders’ Summit, Tokyo, May 2022Source: Getty

It is important to note what we are, and are not, advocating in this report. First, although our focus is on how the Quad should contribute to collective security and defence in the maritime domain, we view this as simply one part of its overall agenda to bolster regional resilience through the provision of “public goods” in a range of areas. We certainly do not advocate reducing the Quad to defence cooperation alone. Second, we do not call for the adoption of a Quad-wide defence strategy, nor do we recommend that enhanced areas of cooperation on maritime security be branded as “Quad” initiatives per se. Both are unnecessary and would risk alarming the Quad’s regional partners without making concrete contributions to collective security. Third, we do not think China should be the sole focus of the Quad’s maritime security agenda. While we urge the Quad to foster certain capabilities, like coordinated anti-submarine warfare, that could be used to deter or defend against Chinese aggression in high-priority scenarios, we see its development of collective maritime security arrangements as having broader applicability.

Finally, although our recommendations are geared towards preparing the Quad to be a more effective collective security actor, we recognise the Quad’s strength will remain a function of its key bilateral relationships and that real-world defence cooperation will rarely involve all of the Quad operating together all of the time. Indeed, the core of our argument is that the Quad has already made important progress at the Quad-minus level towards enabling collective action between its members and has untapped potential to advance this agenda quadrilaterally should its leaders so choose. To this end, we endeavour to explain how the Quad can consciously build out its collective capability so that members can more seamlessly support each other’s maritime security operations or work together in providing regional security goods on the basis of geographical divisions of labour or formally coordinated responsibilities.

The remainder of this report is divided into two parts. In part one, we lay out the current state of the Quad’s maritime security contributions by unpacking its constituent bilateral partnerships. We examine the value of key Quad-minus defence agreements and maritime security arrangements, including the annual Malabar naval exercise, teasing out the gaps in this so-called “cross-bracing” framework for Quad-wide cooperation and detailing the evolution of constraints to a more coordinated Quad maritime security agenda. In part two, we make the case for how the Quad can advance a more collective approach to maritime security in five priority areas: maritime domain awareness, anti-submarine warfare, logistics support, defence industrial and technological cooperation, and maritime capacity building. In each case, we explain the strategic rationale for enhanced quadrilateral action, present detailed recommendations for how this could be achieved, and articulate the value of Quad-wide cooperation in these areas for enhancing maritime security across the Indo-Pacific region.

Part A: The state of play

JS Oumi (centre) conducts a dual Replenishment at Sea with HMAS Arunta (left) and USS Milius during Exercise Malabar 2022Source: Australian Department of Defence

The building blocks of a collective strategy

Although the Quad has eschewed a collective defence agenda in the maritime domain, its members have individually advanced this strategy through a burgeoning range of Quad-minus arrangements at the bilateral and trilateral levels. This process has not been centrally driven by the Quad and will require coordination to meaningfully progress. But it has nonetheless produced a suite of foundational agreements, military exercises and patterns of high-end security cooperation on which a more structured Quad maritime defence strategy can be developed.²

While these are not yet comprehensive, the overall patchwork of cross-bracing security arrangements provides a solid basis for networking and expanding Quad-wide defence cooperation.

At the time of writing, most Quad countries have signed agreements with their counterparts for information- and intelligence-sharing, acquisition and logistics support, and defence industrial and technology cooperation. While these are not yet comprehensive, the overall patchwork of cross-bracing security arrangements provides a solid basis for networking and expanding Quad-wide defence cooperation.³ The annual Malabar naval exercise — which has become synonymous with the Quad since Australia re-joined in 2020, despite its members’ protestations that it is not a formal Quad activity — highlights the growing appetite and potential for security cooperation within the Quad. Meanwhile the increasingly sophisticated nature of high-end maritime security cooperation among the Quad’s constituent bilaterals, albeit at very different speeds and levels of sophistication, represents the building blocks of a nascent collective deterrence capability.

The state of the bilaterals

The United States and its closest regional treaty allies, Japan and Australia, have made great strides towards a strategy of collective deterrence and defence in the maritime domain. Over the past decade, Washington and Tokyo have embarked on a far more integrated approach to defence planning and operations, with Japan’s 2015 Peace and Security legislation expanding the aperture for Tokyo’s participation in defence activities short of homeland defence and prompting an update to alliance guidelines and agreements.⁴ Indeed, even before the watershed changes to Japan’s defence posture brought about by its 2022 National Security Strategy, the US-Japan alliance was steadily accelerating its integration agenda in important ways: exploring combined high-end contingency planning (including joint counterattack and intelligence-sharing planning), launching new joint defence technology development initiatives, expanding the number of joint facilities and stockpiles in Japan, and establishing new mechanisms for joint, real-time information analysis in the maritime domain.⁵ Naval exercises between the United States and Japan have also expanded in scope and scale, with a growing focus on multi-domain anti-submarine warfare (ASW) operations in the Western Pacific, the South China Sea,⁶ and Japan’s Nansei Island chain close to Taiwan.⁷

The US-Australia alliance has similarly become a key node in collective efforts to uphold a favourable balance of power in the region. Bilateral Force Posture Initiatives established in 2011 were updated in 2021 to facilitate expanded US Air Force, Marine Corps, Army and Navy rotations through Australian facilities, and to establish a combined logistics, sustainment, and maintenance enterprise to support high-end military operations in the region.⁸ In a new direction for the alliance, Washington and Canberra are in the early stages of developing more coordinated military- and contingency-planning processes,⁹ as well as deeper forms of defence industrial and technological integration through the trilateral AUKUS partnership which, beyond supporting Australia’s acquisition of nuclear-powered submarines, is designed to generate collective progress on emerging capabilities such as unmanned underwater vehicles, hypersonic missiles, artificial intelligence, quantum and advanced cyber.¹⁰ Meanwhile, Australia-US naval exercises have displayed greater proficiency in “enhanced maritime communication tactics, electronic warfare operations and integrated anti-air, anti-surface operations,”¹¹ with a growing roster of multilateral engagements featuring other capable regional powers like Japan and South Korea through Exercise Sea Dragon and Pacific Vanguard, respectively.

Royal Australian Navy (RAN) amphibious assault ship HMAS Canberra, US Navy Nimitz-class aircraft carrier USS Ronald Reagan, US Navy amphibious assault ship USS Wasp and Japan Maritime Self-Defense Force (JMSDF) helicopter destroyer JS Ise sail in formation with 14 other ships from the US Navy, US Coast Guard, RAN, Royal Canadian Navy and JMSDF during Talisman Sabre 2019Source: Australian Department of Defence

The United States, Japan and Australia are simultaneously working to align these bilateral alliance efforts to “enable higher capability defence exercises and operations” through the Trilateral Strategic Dialogue.¹² A new Joint Vision Statement released in 2022 flagged enhanced training opportunities, more coordinated responses to regional crises, and the development of a trilateral Research, Development, Testing and Evaluation (RDT&E) framework to promote deeper cooperation on advanced technologies and strategic capabilities.¹³ This was followed by an invitation by Australia and the United States to integrate Japan into the Australia-US Force Posture Initiatives announced at AUSMIN 2022.¹⁴ Such efforts to build out this collective defence grouping build on a growing tempo of sophisticated trilateral exercises and operations in the South China Sea and Western Pacific.¹⁵

The United States and India have gradually expanded military cooperation in line with bilateral efforts to sign four foundational security agreements on information-sharing and logistics cooperation, the last of which was secured in 2020.¹⁶ Successive bilateral naval drills have sought to develop “high-calibre integration” between the two partners in areas such as anti-submarine warfare, air defences and maritime domain awareness.¹⁷ Outside of structured exercises, the US and Indian navies have occasionally provided each other with mutual logistics and replenishment support, including, most notably, the decision to service an American P-8A maritime patrol aircraft at Indian facilities on the Andaman and Nicobar Islands during the 2020 India-China stand-off in the Himalayas.¹⁸ Officials have since flagged an increase in coordinated sea patrols, information-sharing in underwater domain awareness, and the use of Indian ports to support US Transport Command assets transiting the Indian Ocean.¹⁹ While India has purchased greater numbers of American maritime platforms in recent years,²⁰ the two countries have also finally begun to pursue co-development projects through the 2012 Defence Technology Trade Initiative (DTTI),²¹ with an inaugural co-development project in air-launched unmanned aerial systems announced in 2021.

Beyond their relations with the United States, Australia, India and Japan have accelerated their own cooperative security frameworks and pursued more complex maritime exercises and operations.

Beyond their relations with the United States, Australia, India and Japan have accelerated their own cooperative security frameworks and pursued more complex maritime exercises and operations. In the past decade, Australia and Japan have significantly widened the aperture of their defence cooperation, elevating bilateral security cooperation to the highest level possible short of a formal alliance. The 2010 Acquisition and Cross-Servicing Agreement (ACSA) was updated in 2017 to bring logistics cooperation “fully into line” with Japan’s 2015 Peace and Security Legislation.²² Significantly, the bilateral Exercise Nichi Gou Trident in 2021 saw Japanese Maritime Self-Defense Force (JMSDF) vessels conduct “asset protection” operations for Royal Australian Navy (RAN) ships, marking the first time such operations were conducted by Japan in support of a non-US partner.²³ The ratification of the 2021 Reciprocal Access Agreement by the Japanese Diet will facilitate more frequent rotations of Japan Air Self-Defense Force (JASDF) fifth-generation fighters and Amphibious Rapid Deployment Brigade personnel through Australian facilities,²⁴ as well as more frequent visits by Australian aircraft and warships to Japanese facilities.

After a relatively slow start, Australia-India maritime defence engagements have also advanced quickly.²⁵ Anti-submarine warfare and maritime domain awareness have become focal points for bilateral engagements, with specialist vessels, submarines and maritime patrol aircraft from both countries now featuring regularly in biennial naval drills.²⁶ These exercises support an emerging pattern of coordinated airborne maritime patrol missions in the Eastern Indian Ocean,²⁷ enabled chiefly by the implementation of the 2020 Mutual Logistics Support Arrangement.²⁸ In early 2022, Australia and India conducted reciprocal visits of P-8 aircraft to Darwin and Goa, respectively, in an effort to further strengthen bilateral ASW and MDA capabilities.²⁹ These engagements included coordinated patrols over strategic waterways off Northern Australia,³⁰ demonstrating the two countries’ mutual interest in monitoring maritime chokepoints in littoral Southeast Asia and the eastern Indian Ocean. India and Australia’s converging interests in ASW and MDA appear to be paving the way for bilateral discussions on “longer-term reciprocal access arrangements” to support combined maritime surveillance operations in the region.³¹

A new type 094A Jin-class nuclear submarine Long March 10 participates in a parade to commemorate the 70th anniversary of the founding of the Chinese People’s Liberation Army Navy, near Qingdao, April 2019Source: Getty

Finally, India and Japan have also advanced bilateral defence ties,³² albeit more slowly, and are moving to deepen cooperation “across the entire spectrum of maritime operations.”³³ The main avenues for this have been the annual Maritime Partnership Exercises and Japan-India Maritime Exercise,³⁴ recent editions of which have showcased real-time information exchanges and divisions of labour for situational and domain awareness during complex, coordinated submarine hunting and over-the-horizon targeting exercises.³⁵ New Delhi and Tokyo have also taken advantage of multilateral naval exercises to operationalise foundational agreements, with the 2020 Agreement Concerning Reciprocal Provision of Supplies and Services implemented for the first time during Exercise MILAN in March 2022.³⁶ Senior leaders have further identified maritime domain awareness as a key vector for enhancing operational cooperation and emphasised the “vast potential” for expanding cooperation on defence equipment and technology beyond its present focus on unmanned ground systems.³⁷

Malabar: A microcosm for the Quad’s transformation

This web of increasingly robust bilateral security cooperation and cross-bracing agreements provides a solid foundation for the Quad to pursue a more collective approach to deterrence and defence in the maritime domain. Although such a strategy has not been officially embraced, the evolution of Exercise Malabar since 2020 — when Australia’s re-inclusion transformed it into the Quad’s only all-member naval activity — highlights just how far the Quad has moved in the direction of high-end maritime security cooperation in a short period of time.³⁸ This offers a preview of what the Quad could achieve in terms of practical maritime security cooperation if its members actively leverage and network the growing potential of their bilateral relationships. Although Exercise Malabar does not represent a formal military agreement between Quad members, it reflects the avenues and platforms that are available to all four members to enhance common interests in the maritime domain.

Figure 1. Quad maritime access locations in the Indo-Pacific and Exercise Malabar locations

Source: USSC

Sources: Department of Defence, India Ministry of Defence, Japan Ministry of Defence, US Department of Defense²⁶⁵

Initially designed to familiarise India and the United States with each other’s procedures for maritime operations,³⁹ Exercise Malabar has recently evolved into a complex set of high-end naval activities.⁴⁰ This has happened relatively quickly. Whereas the 2018 and 2019 drills focused on less complex combined operations and professional training between the United States, India and Japan,⁴¹ following Australia’s re-invitation to Malabar in 2020, the exercise has begun to actively focus on enhancing “integrated maritime operations” between all four Quad countries (see Figure 2).⁴²

Figure 2. Major participants in Exercise Malabar, 2019-2022

Sources: Indian Navy, US Navy²⁶⁶

In practical terms, naval drills have progressed from basic air defence, surface warfare, at-sea replenishment, search-and-rescue and communications exercises to feature increasingly sophisticated anti-submarine warfare (ASW) activities — including submarine integration efforts⁴³ — maritime patrol and reconnaissance, combined operations, interdiction and nascent efforts to explore “joint warfighting planning scenarios.”⁴⁴ Malabar 2021 expanded the scope of drills to explicitly encompass grey zone or “irregular maritime threats” as well as conventional maritime security challenges, reflecting shared concerns over China’s use of maritime militias.⁴⁵ These engagements have allowed Quad countries to practice sharing less-sensitive and unclassified forms of military information relevant to ASW and MDA, including water temperature and seabed geography, in the absence of Quad-wide procedures for sharing classified information for tactical or operational purposes.⁴⁶

The sophistication of these exercises has been mirrored in the quantity and quality of participating platforms. In 2020, Malabar included both Indian and US aircraft carriers for the first time, training for “dual carrier” operations alongside supporting forces from Australia and Japan. A year later, Malabar 2021 became the largest on record with each country dispatching large numbers of advanced air and naval assets (see Figure 1). The 2022 exercises featured maritime patrol aircraft from all four countries for the first time, alongside surface and subsurface vessels outfitted for high-end ASW operations.⁴⁷

The increasingly sophisticated nature of the Malabar exercises, their growing size and scope, and their expanding geographic remit hint at the Quad’s burgeoning willingness to pursue a degree of collective security on high-end maritime security.

Malabar’s growing importance to the Quad has also been reflected in a gradual expansion of its geographic scope. Although the exercises remain true to their origins in maintaining a focus on the Arabian Sea and the Bay of Bengal, they have recently been conducted off the coast of Guam in the Philippines Sea on three occasions (2018, 2021 and 2022), and were formally hosted by Japan in 2022 for the first time.⁴⁸ Taken together, the increasingly sophisticated nature of these exercises, their growing size and scope, and their expanding geographic remit hint at the Quad’s burgeoning willingness to pursue a degree of collective security on high-end maritime security.

These developments have not happened in a vacuum. Beyond Malabar, the Quad has begun to formally explore expanded security cooperation in other defence-adjacent areas. India hosted the first Quad counter-terrorism tabletop exercises in November 2019 to share information, best practices and policy priorities, an engagement repeated most recently in October 2022.⁴⁹ Such activities are useful for stress-testing national response mechanisms and revealing “interagency coordination issues” within and between Quad countries, particularly on information-sharing.⁵⁰ The first Quad Strategic Intelligence Forum was convened in September 2021, immediately prior to the Leaders’ Summit in Washington, featuring the intelligence chiefs of all four countries⁵¹ in what was a striking development given India’s traditional reticence to engage deeply with Quad partners in this domain.⁵² Moreover, the launch of the Quad’s Indo-Pacific Maritime Domain Awareness Initiative in January 2023 — eight months after its announcement — further signals the growing willingness of all four Quad countries to work more seamlessly with each other and with key regional partners to address common maritime security risks.⁵³

Navigating the way forward

Despite the significant progress Quad countries have made towards developing the bilateral building blocks for a collective approach to defence cooperation in the maritime domain, this effort still has a long way to go. At a practical level, the burgeoning array of cross-bracing defence agreements and maritime security activities is incomplete, poorly networked and lacking in common operational standards, particularly when it comes to certain forms of cooperation with India (see Figure 3). As the Quad’s ability to operate cohesively as a maritime deterrent is and will remain a function of the strength and compatibility of its constituent bilaterals, these Quad-minus issues must be addressed to unlock its full potential.

Figure 3. Foundational agreements between Quad members

Sources: Government of Australia, Government of Japan, Government of the United States²⁶⁷

This will not be straightforward. There are longstanding political sensitivities and geostrategic concerns that have traditionally impeded bilateral and multilateral efforts to advance a Quad-wide maritime security agenda. Many of these persist to this day, including different, albeit overlapping, strategic priorities, anxieties over preserving regional support for the Quad, and uneven bureaucratic and domestic political capacities for action.

Fortunately, the tides are turning. There is a growing view within the Quad that China poses a challenge to Indo-Pacific peace and stability that requires collective action and security coordination to address. While Quad countries are highly unlikely to support an explicit collective defence framework within the grouping, constraints on strengthening the cross-bracing agreements and maritime security arrangements that enable deeper operational collaboration are lessening. With a deliberate effort to consolidate, standardise and expand Quad-wide defence cooperation around key maritime security issues of mutual interest, all four Quad countries could expand their operational reach and bolster their independent and collective capacity to deter Chinese aggression.

Incomplete basis for collective action

Closing gaps in the Quad’s underlying framework of cross-bracing defence agreements is essential for enabling collective action between members. At present, the lack of reciprocal access and sophisticated intelligence-sharing agreements between India, on the one hand, and the United States, Japan and Australia on the other, is the most serious omission. Although India has hinted at developing a Reciprocal Access Agreement (RAA) with Australia, this is still under consideration and has not been matched with efforts to explore similar agreements with Japan or the United States. While the US-India Logistics Exchange Memorandum of Agreement (LEMOA) and the Japan-India Acquisition and Cross-Servicing Agreement (ACSA) create some opportunities for military access, these authorities are highly targeted, limited to logistics support and, in the case of the former, are likely subject to additional authorisation by the Indian Government in the event of a US military operation.⁵⁴ An Australia-India General Security of Military Information Agreement (GSOMIA) or its equivalent is yet to be explored, notwithstanding the two countries’ relatively brisk progress on implementing a Mutual Logistics Support Agreement and their preliminary discussions on “longer-term reciprocal access arrangements” to support combined maritime surveillance operations.⁵⁵ Although the United States-India Basic Exchange and Cooperation Agreement (BECA) technically permits “more specific arrangements related to sharing classified and controlled unclassified information,” it is unclear whether these have been explored at the depth required for high-end maritime security cooperation.⁵⁶ Meanwhile, the reflexive “NOFORN” (Not Releasable to Foreign Nationals) classification practices within the US intelligence and export control communities, along with concerns about information protection and processing deficiencies within other Quad intelligence agencies, pose additional barriers to developing a comprehensive information- and intelligence-sharing framework.⁵⁷

An Australian P-8A Poseidon leaves a shadow on the clouds above the Indian OceanSource: Australian Department of Defence

Where foundational agreements between Quad members have yet to reach their full potential, accelerated bilateral efforts are needed to maintain momentum towards collective defence goals. For instance, quickly finalising an update to the 2013 Australia-Japan Information Security Agreement, flagged in 2021, is crucial to advancing newly announced priorities to “develop a common foundation for optimised and agile operational cooperation” or to “strengthen exchanges of strategic assessments” and develop combined contingency responses.⁵⁸ Similarly, timely efforts are required to update US-Japan alliance guidelines and intelligence-sharing procedures in order to implement the “generational” changes that Japan’s 2022 National Security Strategy has laid out for the JSDF and its ability to fight alongside US forces.⁵⁹

Operationalising Quad-minus agreements, however, is often piecemeal and slow. The 2016 US-India LEMOA was debated in New Delhi for nearly a decade before signature,⁶⁰ while it took eight years to translate the two sides’ shared interest in cooperation on space situational awareness from a negotiation into a 2022 Memorandum of Understanding.⁶¹ The limited implementation of these agreements has prevented Washington and New Delhi from engaging more extensively on medium-term challenges and cooperation on issues such as command and control, advanced undersea warfare, water space management, and submarine safety.⁶² This is a familiar story. A US-India working group established in 2018 for the implementation of the Communications, Compatibility and Security Agreement (COMCASA) has not been replicated for BECA or LEMOA,⁶³ limiting opportunities to identify roadblocks to the full implementation of these agreements. It has also limited the development of standardised operating procedures such as guidelines that could push towards greater interoperability by stipulating the circumstances under which US vessels transiting the Indian Ocean would be refuelled by Indian vessels.⁶⁴

Achieving a degree of standardisation across the Quad’s different “classes” of cross-bracing agreements will be required to develop the basis for more cohesive, routinised and unstructured forms of collective maritime action.

Achieving a degree of standardisation across the Quad’s different “classes” of cross-bracing agreements will be required to develop the basis for more cohesive, routinised and unstructured forms of collective maritime action.⁶⁵ At present, all four Quad countries are exploring ways to update bilateral information- and intelligence-sharing agreements to enable more integrated maritime operations.⁶⁶ This must be accompanied by regular efforts to test, refine and practice new protocols to ensure they are operationally viable and to address the qualitative differences across Quad-minus arrangements in the interests of standardising procedures to allow effective information-sharing by all four members.⁶⁷ Similar dynamics apply to logistics arrangements. For instance, provisions in the Australia-India Mutual Logistics Support Arrangement (MLSA) are not specific enough to facilitate the kind of unscripted cooperation that is needed to routinise activities like the reciprocal deployment of P-8 maritime patrol aircraft outside of structured engagements.⁶⁸ Nor is there enough standardisation between the MLSA, on one hand, and the US-India LEMOA and Japan-India ACSA on the other, to enable real-world trilateral or quadrilateral activities. Taken together, the preliminary state of Quad-wide protocols for information and logistics cooperation presents a real impediment to sharing sensitive data on the whereabouts of Chinese vessels across the Indo-Pacific and to collectively mounting operations to track them as part of a combined “Quad-wide” arrangement.⁶⁹

Political and geostrategic constraints

Beyond technical considerations, plugging these gaps and operationalising a more collective approach to maritime deterrence and defence will require Quad countries to overcome a range of lingering political and geostrategic constraints. These include different strategic outlooks, geographic priorities, bureaucratic capacities and geopolitical risk thresholds. While these have impacted specific Quad-minus initiatives on an ad hoc basis, they have also come together in at least three cross-cutting ways to slow and constrain the overall process of developing the building blocks of a maritime security agenda.

First, Quad countries have been extremely cautious in pursuing cross-bracing or collective maritime security engagements that could be construed as part of an explicit Quad-wide defence agenda. There are many reasons for this caution. Foremost among them is that Quad countries are highly sensitive to the views of their regional partners, particularly in Southeast Asia, who fear the Quad could inflame, rather than dampen, security tensions with China.⁷⁰ This is why the Quad has emphasised its “positive and practical agenda [to bring] tangible benefits to the region,” including in the maritime domain, and proceeded very slowly, if at all, on “hard security” cooperation.⁷¹ Canberra and Tokyo appear especially timid about getting ahead of Southeast Asian preferences on the Quad, possibly because each is simultaneously managing regional expectations around their respective defence strategy changes and intensifying security coordination with US forces. At a bureaucratic level, the “innate caution” of Japanese and Indian defence establishments has slowed the pace by which Tokyo and New Delhi have sought to translate shared “strategic objectives into concrete outcomes” across most Quad bilaterals.⁷² Australia and the United States have been mindful of driving maritime security cooperation faster than India is able or willing to proceed, or in ways that outstrip the capacity of Japanese and Indian bureaucracies to operationalise.⁷³ While Indian political and naval leaders have grown more supportive of a robust Quad agenda in the maritime domain, they too are wary of pushing security cooperation further and faster than domestic and regional sensitivities can accommodate.⁷⁴

Ground and aircrew from the Indian Navy, the Royal Australian Air Force and the US Navy in front of three Boeing P-8 aircraft at RAAF Base Darwin during Exercise Kakadu 2022Source: Australian Department of Defence

Second, India’s status as the only non-US ally in the Quad has limited the pace and scope of security cooperation between it and its counterparts. This has been a two-way street. While New Delhi’s aversion to alliances has led it to adopt a cautious approach to advancing bilateral and multilateral defence ties within the Quad;⁷⁵ Canberra, Tokyo and Washington have also been constrained by the practical complications of forging close security ties with a country that sits outside of the US alliance network. This dynamic is apparent in almost all arenas of Quad security cooperation. On reciprocal access arrangements, for example, New Delhi has been cautious about opening military facilities on the Andaman and Nicobar Islands to US and Australian forces, while Washington and Canberra have yet to grant India formal access to Diego Garcia or Darwin outside of planned military exercises. Although this has begun to change with American P-8As refuelling in Port Blair in 2020 and Indian P-8Is deploying to Darwin in 2022, a more streamlined approach to reciprocal access arrangements is needed to elevate bilateral and quadrilateral cooperation in priority areas like ASW and MDA.⁷⁶ The same can be said for information-sharing. India has longstanding concerns about the fairness and reciprocity of sharing intelligence and tactical data with the United States and its allies and remains cautious about sharing information with systems that Pakistan, a US ally, may be able to access. The United States and its allies, for their part, also have longstanding technical reservations about linking secure networks with Indian military platforms based on Russian technology. Both sets of concerns have impeded Quad-minus initiatives. Although these, too, are starting to break down, it will take time and political effort to overcome engrained bureaucratic instincts on all sides.

Third, Quad countries have also been careful to balance the pursuit of collective maritime security with their own proximate interests and strategic priorities, dampening the pace and ambition of some Quad-minus initiatives. This is partly a function of their different, albeit overlapping, geographic priorities: the United States and Japan primarily focused on Northeast Asia and China’s “pacing threat” to Taiwan, Australia on its so-called “immediate region” stretching from the Northeast Indian Ocean through littoral Southeast Asia and the Southwest Pacific, and India on its land borders with China and Pakistan and wider Indian Ocean theatre.⁷⁷ Until recently, different national positions on relations with China — specifically, on how much weight to place on balancing Chinese military power versus preserving economic and political ties — also slowed bilateral and Quad-wide initiatives.⁷⁸ Indeed, Quad countries’ views of one another’s ties with China have played an independent role in holding back some security cooperation, particularly for initiatives in their nascent stage.

JS Oumi and HMAS Arunta conduct a replenishment at sea as INS Kamorta sails into formation during Exercise Malabar 2022Source: Australian Department of Defence

Managing constraints to move forward

While these constraints have not disappeared, many are becoming less pronounced as consensus forms within the Quad that China presents a challenge to regional stability that warrants closer collaboration on maritime security and defence cooperation.⁷⁹ This does not mean all Quad-minus maritime security initiatives are achievable or that a Quad-wide collective defence agenda is on the cards. But it does create an opportunity to leverage deepening alignments, better manage enduring constraints and enhance targeted forms of defence cooperation that advance shared strategic objectives in the maritime domain.

Australia, Japan and the United States have recently begun to shed longstanding concerns about the costs and risks of operational integration in their respective defence strategy updates and new force posture initiatives.⁸⁰ Although this has not foreclosed the need, especially in Australia and Japan, to prioritise specific geographic areas and avoid pre-committing military capabilities to particular crises, the easing of historic reservations about “collective security” has already created space for ambitious coordinated planning and posture arrangements.⁸¹ The March 2023 announcement of the Submarine Rotational Forces-West maritime construct is a tangible expression of what can be achieved between the United States and Australia in this less constrained environment. There is also growing potential for coordinated contingency planning through the Australia-Japan-United States trilateral, which could be leveraged to pursue collective MDA or ASW initiatives on the basis of federated areas of responsibility.

If the Quad consciously pursues a targeted approach to advancing and standardising Quad-wide defence cooperation where key maritime interests converge, it can be a force multiplier for national and collective efforts to deter Chinese aggression and strengthen regional maritime security.

India’s strategic outlook has also evolved in ways that lessen, though do not remove, barriers to deeper security cooperation with its Quad counterparts. A string of deadly incidents along the China-India border have hardened New Delhi’s view of China as a threat, deepened its sense of alignment with the Quad,⁸² and led it to embrace a more active maritime security posture, including an expansion of naval operations that utilise the strategically located Andaman and Nicobar Islands.⁸³ Its growing appreciation of the need for collective action has also seen India expand its repertoire of coordinated maritime patrols, which it now conducts with France in the Western Indian Ocean and with Australia and Indonesia over the Strait of Malacca and the Andaman Sea.⁸⁴ These shifts, to be sure, should not be overstated. India remains committed to strategic autonomy and “retains an enduring aversion toward participating in mutual defense.”⁸⁵ This makes it highly unlikely New Delhi will join its Quad counterparts in a military crisis that does not directly affect its interests.⁸⁶ Short of this high bar, however, India’s growing affinity with the Quad, coupled with its military’s intensifying focus on the maritime environment, creates opportunities for enhanced defence cooperation in specific areas of mutual interest, such as MDA, ASW and logistics support. Even in the event India stays out of a future conflict in the Western Pacific, such collaboration could enhance general deterrence, underwrite new Quad-minus operations, and make a valuable indirect contribution in a crisis.

In sum, there is a geostrategic imperative and an emerging diplomatic opportunity to operationalise the Quad as part of a more coordinated approach to maritime security and defence. This agenda, however, must work within the bounds of certain enduring, albeit lessening, national and multilateral constraints. Overall, Quad countries are likely to remain opposed to pursuing an explicit quadrilateral defence strategy for fear of losing regional support, diluting the Quad’s public goods focus, and undermining their own bureaucratic capacities and strategic preferences. But this should not prevent them from bolstering the existing network of cross-bracing agreements and maritime security arrangements to facilitate deeper operational collaboration across the Indo-Pacific. If the Quad consciously pursues a targeted approach to advancing and standardising Quad-wide defence cooperation where key maritime interests converge, it can be a force multiplier for national and collective efforts to deter Chinese aggression and strengthen regional maritime security. These areas should involve the following five shared priorities: maritime domain awareness, anti-submarine warfare, logistics, defence industrial cooperation and maritime capacity building.

Part B: Advancing a Quad-wide maritime defence agenda

A Japan Maritime Self-Defense Force Seahawk helicopter from JS Inazuma during flying operations as part of Exercise Nichi Gou Trident 2021Source: Australian Department of Defence

Collective maritime domain awareness

Strategic rationale

The Quad requires a more networked, persistent and sophisticated approach to maritime domain awareness (MDA) as a foundation for advancing a more collaborative approach to maritime security. Although MDA cooperation is already a priority for the Quad — stemming from its members’ interests in a comprehensive and reliable MDA picture in their own priority regions — its formal MDA initiatives have so far focused on providing assistance to Indo-Pacific partners dealing with security challenges that are largely constabulary in nature. This is a critical regional “public goods” project. But the Quad and its regional partners would also benefit from a coordinated MDA agenda oriented towards higher-end military capabilities and defence challenges.

Insofar as the capacity for networked maritime domain awareness is a fundamental requirement for more complex forms of defence cooperation, developing this capability within the Quad will provide policymakers with real-time options for higher-end combined operations in the maritime domain.

As China consolidates its strategic presence across the Indo-Pacific (see Figure 4), all four Quad countries require a military-grade operational picture of its expanding deployments and maritime activities. Owing to the vast nature of the Indo-Pacific maritime environment, the difficulty in persistently monitoring PLA-N forces, the burdens of scrutinising key thoroughfares and chokepoints, and the growing capacity constraints faced by all Quad countries, there is a need for the Quad to work together on MDA. This must include deeper information-sharing, coordinated operations and collective efforts to leverage each other’s interoperable capabilities and unique posture, infrastructure and strategic geography. Insofar as the capacity for networked MDA is a fundamental requirement for more complex forms of defence cooperation, developing this capability within the Quad will provide policymakers with real-time options for higher-end combined operations in the maritime domain.⁸⁷

Building a robust common operating picture will require the Quad to pursue a more networked and routinised approach to intelligence, surveillance and reconnaissance (ISR), including combined operations that go beyond structured exercises and efforts to stress-test foundational access, information-sharing and logistics agreements. These lines of effort need not be quadrilateral in a literal sense. Rather, collective MDA operations should be based on a network of bilateral and trilateral arrangements — underpinned by common technical standards and protocols, and formally organised around a geographic division of labour for MDA responsibilities. If successfully developed, a more coordinated and persistent effort to track Chinese military activities across the region would signal the Quad’s capacity for collective action in the maritime domain.

State of play

Quad countries have already demonstrated a shared interest in developing a common regional MDA picture. The Indo-Pacific Maritime Domain Awareness (IPMDA) Initiative launched at the Quad Leaders’ Summit of 2022 proposed to trace “dark shipping” and “other tactical-level activities” through commercial satellite networks to deliver a “near-real-time, integrated, and cost-effective maritime domain awareness picture” to regional partners, with the first satellite array launched in January 2023.⁸⁸ The IPMDA marked a step towards formalising patterns of information exchange and wider cooperation that will generate second-order benefits for a more robust collective defence agenda in future, even if the initiative itself is not defence-oriented.⁸⁹ However, the information gathered through the IPMDA is unclassified and is processed and disseminated through “public goods” mechanisms like US SeaVision and regional Information Fusion Centres in the Indian Ocean, Southeast Asia and the Pacific Islands,⁹⁰ none of which are integrated with their counterparts.⁹¹ This means that IPMDA does not facilitate the sharing of sensitive information from military sensors, nor does it include a dedicated joint assessments component for Quad countries to evaluate shared information from an operational standpoint. While this is the right approach for delivering on the Quad’s commitment to providing information to regional countries that addresses non-traditional security challenges, it is inadequate for higher-end defence objectives. Building a common military-grade MDA picture between the four countries to effectively track PLA movements will require a dedicated, Quad-only line of effort that goes beyond leveraging commercial satellite data.

To date, it is only at the Quad-minus level that Australia, India, Japan and the United States are moving towards more collective approaches to higher-grade MDA cooperation. To be sure, Malabar exercises since 2020 have increasingly focused on building “combined air and maritime domain awareness” capacity, with maritime patrol aircraft from all four countries participating for the first time in 2022.⁹² But all the sophisticated MDA engagements take place at the bilateral level where various country pairings incorporate real-time information exchanges, over-the-horizon targeting, and divisions of operational and geographical labour.⁹³ Furthermore, the foundational agreements in access, logistics, sustainment and information-sharing that provide the bureaucratic and legal foundation for turning these exercises into operations are almost exclusively bilateral (see Figure 3). These have paved the way for the deployment of an American P-8A to the Andaman and Nicobar Islands at the height of China-India tensions on the Himalayan Border in 2020,⁹⁴ as well as reciprocal visits by Australian and Indian P-8s to one another’s air bases in Darwin and Goa in 2022 as part of a combined initiative to “build operational maritime domain awareness.”⁹⁵ Such activities are a starting point for new forms of coordinated operations that could extend the range of national capabilities and provide more fidelity on Chinese movements through important regional chokepoints and waterways,⁹⁶ leveraging platform commonality and unique geographies to maximise the strategic pay-offs of combined MDA activities.

P-8I, P-8A and P-1 aircraft from Australia, the United States, Japan and India fly over HMAS Stalwart and INS Shivalik during Exercise Malabar 2022Source: Australian Department of Defence

Even so, these developments are only preliminary. Truly operationalising the Quad’s converging interests in building a more comprehensive and persistent shared MDA picture — one that is capable of tracking Chinese naval activities — will require working at another level of sophistication. Though the four countries occasionally exchange operational MDA information in the ways outlined above, this occurs on a largely ad hoc basis and at the bilateral level (and, in the case of information-sharing between India and the others, rarely in real-time).⁹⁷ Moreover, when it comes to India, the nature of individual bilateral arrangements can actually have a “lowest common denominator” effect on wider cooperation among Quad partners. For instance, the absence of a US-India COMCASA prior to 2018 complicated India’s ability to share real-time tactical information not only with the United States but also with Australia and Japan, owing to those countries’ extensive use of US tactical information-sharing networks.⁹⁸

Crucially, the absence of a common operating picture limits India’s capacity to engage in more complex MDA exercises and operations, including the collective tracking of Chinese naval activities by Quad maritime patrol aircraft through critical waterways.⁹⁹ Even with COMCASA in place, India’s reservation over incorporating US encrypted data link hardware, like Link 16, and barriers to accessing US defence technology mean these limitations still largely apply.¹⁰⁰ Today’s patchwork of disparate data link architectures might be “good enough” for peacetime naval cooperation, including federated maritime security patrols. But such arrangements are insufficient for developing the kind of real-time military-grade common operating picture necessary for more complex and unscripted forms of real-world cooperation between India and its three Quad partners, such as coordinated ASW operations (see next chapter).¹⁰¹

Recommendations

1. Develop a networked and persistent approach to maritime domain awareness (MDA) as a foundation for tracking maritime activities of interest across geographic areas of responsibility, including as a baseline for potential coordinated efforts to build a comprehensive, real-time picture of Chinese military movements.
2. Discuss the limitations of existing tactical data link arrangements within the Quad, and work towards an interface protocol to govern information-sharing between all Quad partners, with particular attention paid to the commonality of hardware and software or, at the least, interoperability of different tools.
   
   Conducting sophisticated MDA operations collectively will require Quad countries to upgrade their respective information-sharing architectures. Even if the end-state of such cooperation is premised on a network of largely bilateral operations and arrangements, robust information-sharing processes will be crucial to developing the common operating picture and shared assessments on which these activities would draw. Establishing a more secure, encrypted information exchange network between the four countries will be critical. This exists between Australia, Japan and the United States, but standards of information-sharing with India remain the outlier. Facilitating such exchanges will require accelerating nascent efforts to incorporate US-origin tactical data link capabilities onto relevant Indian platforms, and/or the development of an interface protocol to determine parameters for information exchange that address Indian sensitivities around over-sharing tactical information.¹⁰² On a practical level, Quad countries should pursue solutions to these data-sharing hardware challenges with the Indian Navy that are better than “good enough” but less than seamless or perfect.
3. Update bilateral information security agreements and pursue a multi-party agreement to enable Quad countries to develop a more holistic picture of military activities of interest across the Indo-Pacific.
   
   Quad countries could also update their respective bilateral information security agreements and, ideally, develop a multi-party agreement akin to the Australia-Japan-United States Trilateral Information Sharing Agreement (TISA). This agreement was signed to “enable higher capability defence exercises and operations” in the service of improving shared situational awareness across the region,¹⁰³ allowing the three navies to share classified information to develop a more holistic picture of potentially hostile maritime activities, including Chinese movements in places like the South China Sea.¹⁰⁴ Though a politically difficult proposition for India, such an arrangement would nevertheless help minimise the challenges of coordination across different bilateral information silos, and would not preclude India from moderating its participation in Quad-related MDA activities depending on political thresholds. It could also provide a multilateral basis for the hardware integration efforts outlined above. It is worth acknowledging that this kind of sharing is, ultimately, built upon a foundation of operational trust which may take some time yet to build.
4. Selectively integrate Quad countries’ strategically-located coastal facilities, island territories and regional access locations to conduct more persistent and coordinated MDA operations throughout the region; and jointly assess operational requirements of hosting and replenishing one another’s MDA assets.
   
   The Quad could work towards further leveraging its members’ coastal facilities, island territories and regional access locations to conduct more persistent and coordinated MDA operations in the region,¹⁰⁵ working within the bounds of present-day technical and political constraints. More frequent ship and aircraft visits to one another’s ports and airstrips would help to stress-test existing access, information-sharing and logistics frameworks in ways that structured exercises cannot. This would ensure that underlying agreements are fit to support a more collaborative approach to maritime surveillance underpinned by a network of region-wide staging locations.¹⁰⁶
   
   As a starting point, all four countries could build visits to one another’s island bases and regional access locations into existing patterns of operation.¹⁰⁷ Bases and access locations on India’s Andaman and Nicobar Islands, Australia’s Cocos (Keeling) Islands, Japan’s Okinawan Island Chain, and US facilities in Japan, the Philippines, Diego Garcia and Guam all provide ready access for Quad ships and aircraft to extend the range and duration of patrols around key waterways and chokepoints (see Figure 1), especially if combined with robust maintenance, sustainment and overhaul complexes. In operational terms, India and Australia could expand their current maritime domain awareness initiative to conduct reciprocal visits and coordinated patrols in the Northeastern Indian Ocean.¹⁰⁸ Japanese P-3C Orion or Kawasaki P-1 could similarly take advantage of these locations to conduct coordinated or joint operations with Australian and Indian counterparts en route to or on return from rotational deployments to JSDF Base Djibouti or following deployments to the South China Sea.¹⁰⁹ In the Western Pacific, Australia, Japan, and the United States could expand the scope, duration and sophistication of “interchangeable” patrols in littoral Southeast Asia and the Pacific by leveraging ports and airstrips in northern Australia, Singapore, the Philippines, Guam and Japan’s southern islands.
5. Set up formal MDA and ISR initiatives that combine shared access, information-sharing and analysis, and platform interoperability to create a common operating picture within geographically-defined Quad groupings, including by incorporating common UAV platforms.
   
   Finally, Quad countries should pursue more formalised MDA and ISR initiatives that sit at the intersection of shared access, information-sharing and analysis, and platform interoperability. The new US-Japan Bilateral Intelligence Analysis Cell, which is designed to enable American and Japanese personnel to “jointly analyse and process information gathered from assets of both countries,” provides a useful template for how this might work.¹¹⁰ This initiative involves ISR missions over the East China Sea by American MQ-9 Reaper and SeaGuardian UAVs taking off from Kanoya Air Base, Japan,¹¹¹ with the JASDF set to integrate its own drones in the operations in the coming year.¹¹² Exploring similar arrangements within the Australia-India Maritime Surveillance Initiative, US-India MDA cooperation in the Indian Ocean, or Australia-Japan-United States ISR operations in the South China Sea would be a logical step, particularly as greater numbers of UAVs are acquired by all four countries.¹¹³ Focusing on joint analysis rather than joint contingency planning would allow for a common understanding of threats and challenges,¹¹⁴ and could offset some of the technical difficulties of real-time information sharing. Such initiatives would require revising existing access agreements and inking new Status of Forces agreements, which have been raised in the Australia-India context¹¹⁵ but may not be politically feasible between all four partners at this time.

Coordinated anti-submarine warfare operations

Strategic rationale

Developing the capabilities for coordinated anti-submarine warfare (ASW) should be a priority maritime security task for the Quad. China’s increasingly large and sophisticated fleet of attack submarines (see Figure 6) is expected to number between 65 and 70 boats throughout the 2020s and could present a major challenge to freedom of access throughout the Indo-Pacific in a contingency.¹¹⁶ Although China is still modernising its underwater capabilities, the rapid expansion of its submarine-related activities is of great concern to all four Quad nations (see Figure 4). The United States has tracked Chinese oceanographic vessels conducting seabed mapping operations in the waters around US bases in Guam and Hawaii, operations which lay the navigational groundwork for submarine deployments.¹¹⁷ India is grappling with the PLA-N’s growing submarine footprint in the Indian Ocean, as well as with Chinese seabed mapping operations observed around strategic waterways in the Eastern Indian Ocean.¹¹⁸ Japan faces regular Chinese submarine activity along its island chains, including in the East China Sea.¹¹⁹ Recent incidents between the PLA-N and Australian ships and aircraft in the Arafura and South China Seas have highlighted the growing assertiveness of Chinese submarine operations, with concerns rising in Canberra regarding PLA-N submarines and unmanned undersea vehicles (UUVs) operating in Australia’s northern approaches.¹²⁰

Figure 4. Snapshot of select Chinese maritime access and activities in the Indo-Pacific

Source: USSC

Sources: ABC News, The Diplomat, Forbes, Naval News, Nikkei Asia, South China Morning Post, The Economic Times, The Hindustan Times, The Times of India, USNI News²⁶⁸

Against this backdrop, the Quad should work towards developing a collective capacity to track Chinese submarines across geographically defined areas of responsibility for better awareness.¹²¹ As with collective MDA efforts, such an approach would see Quad militaries share and “hand off” monitoring and surveillance responsibilities with their counterparts on a more consistent and structured basis than in the past.¹²² This kind of cooperation is not without precedent. The United States and Japan pursued a federated approach to ASW during the Cold War as part of their collective efforts to check Soviet submarine activities in Northeast Asia, an arrangement that included the allocation of roles and responsibilities for chokepoint security and SLOC protection, and which, in turn, informed bilateral force structure planning and decision-making.¹²³ Today, there is growing support in Australia, Japan and the United States for a more federated approach to regional ASW and strong interest in this agenda among some Indian strategists.¹²⁴ But enabling the Quad to operate at high levels of integration will not be easy. A collective ASW framework that harnesses the Quad’s capacity, capability and access locations will require sharing sensitive mission and tactical data, combined operational planning, more sophisticated exercises, new access arrangements, and coordinated and routinised ASW patrols across the region.¹²⁵

State of play

Anti-submarine warfare is already a prominent aspect of Quad activities in Exercise Malabar and other engagements. In recent years, Malabar has seen growing numbers of submarines, ASW surface vessels and maritime patrol aircraft take part in increasingly sophisticated activities, such as “submarine integration” and maritime patrol and reconnaissance training (see Figure 2).¹²⁶ As with most Quad cooperation, these engagements build on developments at the bilateral and trilateral level where ASW is a clear priority. For instance, the development of a “shared ASW capability,” including the tracking of PLA-N submarines, has been a feature of US-India naval engagements since at least 2016.¹²⁷ Senior US officials see collective ASW as a key vector for alliance modernisation with Japan;¹²⁸ while undersea warfare occupies pride of place in US-Australia naval exercises and the AUKUS partnership.¹²⁹ Bilateral Australia-Japan and India-Japan naval exercises have demonstrated a similar sharpening of focus on ASW activities in recent years.¹³⁰

A Royal Australian Air Force aviator marshals an Indian Navy P-8I Neptune maritime patrol aircraft to a stop at RAAF Base Darwin, April 2022 Source: Australian Department of Defence

Other military drills have recently highlighted Quad countries’ burgeoning interest in developing collective approaches to ASW in the Indo-Pacific, including by leveraging one another’s physical infrastructure and common platforms. The United States and Japan have spearheaded multi-domain ASW operations in the Western Pacific, the South China Sea and the Nansei Island chain close to Taiwan,¹³¹ some of which have featured Australian naval assets.¹³² The US Navy has begun to undertake more complex submarine logistics, sustainment and weapons-loading exercises out of Australia’s HMAS Stirling,¹³³ activities that will support the forward deployment of US Virginia-class submarines from 2027 and the home-basing of Australian SSNs in the 2030s.¹³⁴ Australian and Indian P-8s have conducted reciprocal deployments to one another’s facilities outside of routine exercises to “practice anti-submarine warfare manoeuvres.”¹³⁵ Taken together, these activities point to the Quad’s growing appreciation of the benefits of leveraging access arrangements and platform commonality to maximise the reach and effectiveness of national and collective ASW operations.

Yet, progress in these different Quad-minus ASW relationships is not equal. When it comes to operationalising a collective ASW capacity, trilateral efforts between Australia, Japan and the United States are leading the way. Indeed, the three countries recently conducted sophisticated theatre ASW exercises to “remove friction points between forces” and hone “combined information sharing, coordination, and communication.”¹³⁶ Such engagements are designed to facilitate “real-world integration” through reciprocal officer embarkation, expanding mutual submarine logistics support, and smoothing communication paths between the three navies.¹³⁷ These engagements are consistent with top-level trilateral commitments to increase the complexity of joint naval exercises and to make more effective use of the 2016 Trilateral Information-Sharing Agreement.¹³⁸ They build on the high levels of strategic and operational trust in the US-Australia and US-Japan alliances, the recent deepening of Australia-Japan security ties, and nearly two decades of efforts to foster trilateral naval cooperation, including on ASW.¹³⁹

The Quad’s primary challenge in realising a more robust anti-submarine warfare agenda is to find effective ways to extend these developments to include India.

In this context, the Quad’s primary challenge in realising a more robust ASW agenda is to find effective ways to extend these developments to include India. Nascent cooperation in sensitive areas like underwater domain awareness (UDA) in Quad-minus engagements that incorporate India is an encouraging sign. High-end navy-to-navy cooperation on UDA has grown in prominence in the India-US bilateral agenda¹⁴⁰ with the “exchange of sensitive maritime information on… Chinese submarine transit[s] of the Indian Ocean” identified as a key area for further work.¹⁴¹ Notwithstanding India’s progress on this front, however, political and technical barriers continue to limit the sort of persistent real-time information-sharing and operational capability required to underwrite higher-value collective ASW operations. While there is some support in India for collective approaches to operational ASW problems, New Delhi tends to prefer these to focus on joint assessments rather than joint collection due to the nascent stage of quadrilateral military information-sharing arrangements and ongoing reservations around sharing sensitive data with US systems.¹⁴² Given the prevalence of Russian hardware across India’s naval force structure, concerns over the security of information are, in many ways, mutual.¹⁴³

Japan Coast Guard Unmanned Aerial Vehicle SeaGuardian and JMSDF P-3C at Hachinohe Air Base Source: Japan Maritime Self-Defense Force

Practically speaking, the outstanding element to successful collective Quad ASW remains a secure and permanent data link solution that enables real-time sharing of data and information of tactical relevance. The fact that Australia, India and the United States each fly variants of the P-8 Poseidon maritime patrol aircraft and MH-60R helicopter — both of which are interoperable with Japan’s Kawasaki P-1 aircraft and SH-60R helicopter (see Figure 5) — naturally aids combined operations. However, without alignment in communications and tactical software, operations themselves will remain difficult to integrate. While India’s US-origin ASW platforms now carry interoperable communications and data link equipment, this still falls short of what is required to undertake genuinely coordinated ASW operations.¹⁴⁴ The patchy implementation of bilateral access, information-sharing and logistics agreements — and their absence in certain Quad pairings — also limits the extent to which combined ASW activities can take place at short notice and without significant operational restrictions (see Figure 3).

Figure 5. Maritime capabilities of Quad members, number of assets

Source: USSC

Sources: International Institute for Strategic Studies, Naval Vessel Register²⁶⁹

Figure 6. Number of attack submarines, Quad v. China

Source: USSC

Source: International Institute for Strategic Studies, Naval Vessel Register²⁷⁰

Recommendations

1. Forge a collective anti-submarine warfare capability by developing higher levels of interoperability and more persistent patterns of unscripted cooperation to include tracking and “handing off” overwatch of submarines transiting geographically defined areas of responsibility.
   
   At its most mature, the Quad could present China with a formidable anti-submarine deterrent by developing higher levels of interoperability and more persistent patterns of unscripted cooperation, should the need arise. Even the continued emphasis on combined ASW training should have a deterrent effect as all four Quad partners hone their capabilities in the undersea domain. Though there remain significant political and operational hurdles to joint ASW operations of the highest order, Quad countries are already taking steps towards operationalising more collaborative and persistent surveillance arrangements. The Quad partners should be capable of tracking the movement of PLA-N submarines through key thoroughfares and chokepoints, and “handing off” overwatch of these movements to one another as these targets transit different geographic areas of responsibility.
2. Develop mechanisms to conduct joint assessments of underwater domain awareness (UDA) data gathered by national sensors, towed acoustic arrays, ASW aircraft and unmanned vehicles, focusing on agreed-upon areas of operation with an eye towards joint collection in the future.
   
   Most ambitiously, Quad navies should explore options to further develop joint undersea surveillance networks. Plans by all four Quad countries to introduce greater numbers of unmanned systems into their ASW operations could provide avenues for collaboration on operational concept development, with potential flow-on benefits for joint or coordinated operations. For example, Australia, India, and Japan intend to procure greater numbers of maritime UAVs like the MQ-9B SeaGuardian, while all four countries are developing extra-large unmanned underwater vehicles (XLUUVs) to provide more persistent and cost-effective ASW, ISR and kinetic effects in the undersea domain.¹⁴⁵ The potential interoperability and operational endurance afforded by these platforms should provide further opportunities to expand or augment Quad or Quad-minus ASW and UDA activities, such as coordinated operations to persistently monitor key strategic waterways. Each country’s underwater training ranges should be leveraged to develop and test common operational concepts for these assets.¹⁴⁶
3. Establish service- or bureaucratic-level mechanisms for conducting four-way combined assessments of underwater domain information from select areas, and work towards a formal classified sharing network for the development and dissemination of key submarine-related intelligence.
   
   Upgrading information-sharing arrangements will be key to a more comprehensive Quad ASW agenda. As an alternative to current hurdles in sharing intelligence, the Quad could focus on developing service- or bureaucratic-level mechanisms for conducting four-way joint assessments of domain information from select geographic areas. As with MDA, this could emulate the US-Japan Bilateral Intelligence Analysis cell,¹⁴⁷ though with a focus on honing a collective approach to the information “outputs” of combined ISR activities rather than the “inputs” provided by collection and real-time data sharing. At a more ambitious level, the Quad could seek to develop a formal classified sharing network for the development and dissemination of key submarine-related intelligence. A dedicated system, held at the appropriate level of classification, would aid the development of a common real-time operating picture extending from the Indian Ocean into the Western Pacific, allowing all four partners to maintain considerably higher fidelity awareness of PLAN submarine movements throughout the region. This could begin as a standalone “proof of concept” Quad or Quad-minus initiative including India, and be upgraded to an in-person watch floor pending its success and the status of political reservations.¹⁴⁸
4. Identify the necessary upgrades to existing bilateral agreements and access locations required to support more frequent coordinated aerial ASW activities.
   
   Finally, Quad countries should also conduct a joint assessment of the basing options and legal frameworks required to sustain more frequent aerial ASW operations across the region. As discussed, the makings of this are already emerging through reciprocal visits by maritime patrol aircraft among all four nations.¹⁴⁹ Going forward, instructive models for advancing such engagements can be found outside the Quad context. For example, Indian P-8Is fly sorties and undertake “joint surveillance and patrolling operations” with French aircraft and surface vessels in the Southern and Western Indian Ocean from the French territory of La Reunion Island — activities which often include the embarkation of naval personnel on each other’s aircraft.¹⁵⁰ Similar operational models can be found in Europe. The trilateral maritime surveillance initiative between the United Kingdom, the United States and Norway — stood up in 2016 to monitor Russian activity in the Arctic — leverages access locations in all three countries to sustain coordinated P-8 ASW and MDA operations and to conduct joint maintenance and training activities.¹⁵¹ Exploring such options in a Quad or Quad-minus context should be a top priority.

Nuclear submarine USS Springfield prepares to berth outboard of USS Frank Cable at Fleet Base WestSource: Australian Department of Defence

Integrated maritime logistics

Strategic rationale

A more integrated approach to maritime logistics is a critical, practical and achievable goal for underwriting enhanced Quad cooperation in the maritime domain. Where maritime security offers a degree of plausible deniability for military cooperation, logistics maximises that utility and offers a translatable skillset useful alongside the entire spectrum of military options. The so-called “five R’s” of logistics — refuel, rearm, resupply, repair and revive — are essential capabilities for any military.¹⁵² The ability to share these resources and services among Quad countries to support activities ranging from humanitarian aid and disaster relief to higher-end military operations would significantly enhance their individual and combined abilities to operate effectively across the Indo-Pacific’s vast maritime space. Crucially, a distributed network of Quad logistics capabilities would create flexibility and resilience for all in peacetime, and enable more persistent and collective deterrence operations.

Such an effort has rarely been more necessary. The Pentagon’s assessment of US Indo-Pacific logistics infrastructure is dire, with budget planning documents connected to the Pacific Deterrence Initiative stating that “[c]urrent theater logistics posture and capability to sustain the force are inadequate to support operations specifically in a contested environment.”¹⁵³ This is in line with assessments highlighting the US Navy’s “Achilles heel” of vast shortfalls in the size and material readiness of its sealift fleet.¹⁵⁴ Australia, India and Japan operate only small numbers of auxiliary vessels (see Figure 5), while dedicated dry cargo and ammunition ships are only found in the US Navy, limiting the four countries’ capacity to sustain independent — let alone combined — military operations in distant waters. Furthermore, all four countries face challenges with maintaining sufficient fuel stockpiles, including strategic reserves, to support higher operational tempos even in peacetime.¹⁵⁵ In short, in a potential conflict where any combination of Quad members square off against the PLA, logistics will be heavily contested, and existing oilers and logistics connectors will make for a small handful of high-value and extremely vulnerable targets.

Such cooperation would require China to reckon with the prospect of a Quad that is at least capable of providing mutual support in crisis or conflict situations, even if its members are not aligned on policy or directly involved in combined operations.

In this context, logistics cooperation among the Quad should create options for partners to marshal more credible seapower behind a common purpose. While these abilities are not in themselves of deterrent value, they are the foundation upon which a collective deterrent posture must rest — as navies that cannot sustain themselves will not be regarded as a credible deterrent by an adversary. The Quad should therefore build toward a combined capability to seamlessly refuel, resupply and repair ships and aircraft from any of its members and foster the ability to do so at very short notice. Such cooperation would require China to reckon with the prospect of a Quad that is at least capable of providing mutual support in crisis or conflict situations, even if its members are not aligned on policy or directly involved in combined operations.

State of play

All four Quad countries have sought to deepen maritime logistics cooperation with each other, in part to offset capacity or budgetary shortfalls and to extend their respective operational reach. These efforts are supported by bilateral ACSAs or their equivalents (see Figure 3), which create the administrative pathways for sharing billeting, fuel or other critical equipment, and provide a framework for more sophisticated logistics cooperation between Quad members.¹⁵⁶ The 2021 and 2022 editions of Exercise Malabar saw various combinations of Quad replenishment vessels, submarines and major surface combatants engage in sophisticated logistics engagements, such as dual replenishment and helicopter cross-decking, as part of a joint surface action, with Australian, Indian and Japanese oilers and replenishment vessels sharing responsibility for providing primary support to these task groups.¹⁵⁷ Similar engagements have taken place in “Quad Plus” exercises, most recently during combined combat capability drills as part of Exercise La Perouse with British and French participation, during which India provided the sole source of at-sea replenishment.¹⁵⁸

An aircrewman watches out of HMAS Arunta’s MH-60R helicopter ‘Athena’ as HMAS Arunta and USS Milius conduct a dual replenishment at sea with JS Oumi during Exercise Malabar 2022Source: Australian Department of Defence

These sorts of complex exercises are made possible by significant progress at the bilateral and trilateral levels. Most notably, the United States, Japan and Australia have recently conducted integrated logistics drills designed to improve their collective “sustainment capability and high-end warfighting” capacity,¹⁵⁹ building on existing bilateral logistics interoperability and integration initiatives.¹⁶⁰ All three countries have also sought to deepen their logistics engagement with India. In the wake of the Indian Navy’s adoption of NATO fuel standards, a supplementary agreement to the 2016 US-India LEMOA signed in 2021 provides a long-term basis for more seamless fuel transfers between the two navies.¹⁶¹ The 2020 India-Japan ACSA has been leveraged to sustain successive JMSDF Indo-Pacific deployments in the Indian Ocean through port visits and at-sea replenishments.¹⁶² Meanwhile, Australia and India have committed to more tangible “operational logistics support” to underwrite “greater combined responsiveness” to regional contingencies,¹⁶³ including more frequent reciprocal P-8 visits.¹⁶⁴

Encouragingly, maintenance, repair and overhaul (MRO) initiatives have also become increasingly prominent in Quad bilateral meetings, particularly those featuring the United States. This is a significant development considering the absence of US shipyards west of Guam,¹⁶⁵ and given the longstanding capacity pressures on US MRO facilities in Japan brought about by greater numbers of US ships rotating and forward deployed to the country.¹⁶⁶ In August 2022, a US dry cargo ship arrived in Chennai, India, for repairs, marking the first time a bilateral commitment to conduct MRO on US Sealift Command vessels in Indian shipyards was operationalised.¹⁶⁷ Meanwhile, the March 2023 announcement that US submarines would rotate through Australian facilities as part of the AUKUS arrangement highlighted the growing importance of the US-Australia Logistics, Sustainment and Maintenance enterprise, a core element of the allies’ expanded Force Posture Initiatives.¹⁶⁸ With Japan now integrating into US-Australia force posture arrangements, these facilities could one day be used to refuel, rearm, repair, maintain and overhaul JMSDF vessels.¹⁶⁹ Significantly, these MRO initiatives are being accompanied by efforts to expand the size and distribution of fuel stockpiles, strategic reserves and resupply points across Australia’s northern territory and throughout Japan’s Nansei Island Chain.¹⁷⁰

Testing the limits of existing logistics and sustainment agreements will be crucial to developing a functional Quad logistics enterprise capable of supporting less planned and more complex patterns of cooperation.

All of this is an encouraging sign that the Quad partners are approaching critical logistics capabilities from a standard position. Yet, while progress is evident, work remains to be done. Across the board, testing the limits of existing logistics and sustainment agreements will be crucial to developing a functional Quad logistics enterprise capable of supporting less planned and more complex patterns of cooperation. Indeed, unstructured engagements outside of the realm of joint exercises have already highlighted shortcomings in existing frameworks. For instance, the October 2020 visit of a US P-8A to India’s Andaman and Nicobar Islands highlighted the need for a longer-term implementing arrangement for fuel transfers and other interactions beyond the “very basic” provisions of the original agreement.¹⁷¹ To date, the absence of a dedicated LEMOA working group has limited opportunities to identify implementation roadblocks or develop “standardized operating procedures” to improve logistics cooperation.¹⁷² The increasing tempo of reciprocal Australia-India P-8 activities is also likely to reveal similar challenges,¹⁷³ as are more frequent engagements between the Indian and Japanese navies.¹⁷⁴

Fully implementing and better networking these initiatives is essential if the Quad is to advance any kind of maritime security agenda, whether that be operationalising its 2022 HADR guidelines or prospective maritime defence initiatives.¹⁷⁵ In this respect, efforts to standardise and enact the Quad’s various logistics agreements in uniform ways should be a priority. This is no easy task. The agreements themselves are typically arranged by fleet-level staff and discussed in venues like fleet talks. But in practice, logistics sharing activities tend to take place haphazardly or on an ad hoc basis, where efforts to operationalise new agreements are subject to individual initiative (as opposed to being driven in a top-down way with identified performance indicators) and may be under-utilised as a result. Planning and implementation rigour is required to effectively marshal the benefits of existing logistics, maintenance, and sustainment initiatives behind a Quad maritime security agenda.

Recommendations

1. The Quad should develop the collective capacity to seamlessly refuel, resupply and repair maritime assets from any member on short notice, and formally commit to this agenda at the political and operational level.
   
   The Quad should develop the capacity to seamlessly refuel, resupply and repair ships from any member on short notice. This will require streamlining bureaucratic processes and overcoming sources of institutional resistance to conducting these tasks more frequently and beyond the format of structured exercises. Sustained commitment at the political and operational levels will be integral to incorporating combined logistics into routine movement and maintenance planning. Long-term organisational plans must make these commitments explicit, and their progress reported upward to government to incentivise military leaders to execute the plan’s intent. As with many other tasks, information sharing both ahead of time and in real-time will be critical to actualising a Quad maritime logistics enterprise.
2. Establish a Quad Logistics Coordination Cell within the US Navy’s Commander, Logistics Group Western Pacific that incorporates all four partners and performs logistics planning for the Indian and Pacific Oceans, using combined maintenance and resupply capabilities on a regular basis.
   
   The US Navy’s Commander, Logistics Group Western Pacific (COMLOGWESTPAC) represents perhaps the most developed mechanism for formally integrating a Quad logistics capacity, short of establishing a logistics unit within the Quad itself. COMLOGWESTPAC hosts foreign liaison officers on formal or informal arrangements within its headquarters to schedule replenishment at sea for critical stores like fuel, food and water.¹⁷⁶ These liaisons identify opportunities to synchronise logistics activities or conduct combined logistics operations, driving initiatives like “interchangeable logistics” planning between the likes of France, Japan and the United States to improve the “reach, speed and reliability” of their respective sustainment fleets.¹⁷⁷ A similar approach should be applied to the Quad. At present, Japan and Australia have designated representatives in COMLOGWESTPAC’s multinational logistics cell. Incorporating an Indian liaison officer into that construct would help develop stronger staff linkages to inform and facilitate greater logistics cooperation between Quad countries.¹⁷⁸
3. Elevate maritime logistics discussions to the Quad Maritime Security Working Group to promote information-sharing on bilateral and trilateral logistics activities, pursue opportunities for aligning or networking concurrent activities, and develop options for Quad logistics planning, exercises and operations.
   
   Concurrently, the Quad Maritime Security Working Group (MSWG) should serve as a forum for reviewing the provisions and implementation status of bilateral access and logistics agreements to ensure that this latticework can support consistent Quad logistics engagements and operations. Though recent editions of Exercise Malabar have served as forums for “validating” bilateral logistics support agreements between the four countries,¹⁷⁹ these engagements will not in themselves lead to necessary revisions or variations in the interests of further streamlining this cooperation. Specifically, the Quad MSWG should focus on: promoting information-sharing on bilateral and trilateral activities, considering opportunities for aligning or networking concurrent logistics activities, and exploring options for quadrilateral logistics planning and for at-sea and table-top exercises. Knowing where replenishment ships or vessels requiring maintenance will be in the future allows naval planners to properly build their scheme of manoeuvre (where they will be and when). Considering the demands placed upon the replenishment and sustainment fleets across the Quad by operational patrols, unilateral exercises, combined activities and required maintenance periods, this process requires significant lead time. At a minimum, the Quad should consider the frequency with which its members transit key geographic chokepoints. Understanding where partner vessels operate most frequently will create increased predictability for resupply, cutting down transit times for logistics vessels. This mission data should be used to plan deployments for those vessels to maximise cooperation opportunities and reduce the need for redundancy, minimising wear and tear on scarce assets. Information shared on the above could be disseminated via fleet talks and national chains of command.
4. Conduct a Quad-wide equipment interoperability review to ensure logistics compatibility and procedural standardisation; and support this with a formal framework and requirement for placing Quad liaisons on one another’s logistics vessels to encourage familiarity and exchange best practices.
   
   Furthermore, all four partners should conduct an equipment interoperability review to ensure sustained compatibilities between their respective capabilities, methods and procedures. Verifications and certifications for activities like ship-to-ship refuelling and helicopter cross-decking are straightforward to conduct, and have featured in Exercise Malabar for some years.¹⁸⁰ Nevertheless, the process of ensuring ongoing compatibility is vital to safe and effective operations, particularly as Quad countries introduce new maritime capabilities and make variations to operating standards and procedures for things as banal as fuel quality.¹⁸¹ In this respect, Quad liaison officers and crew swaps between logistics support vessels — along the lines of those flagged in the 2020 USN-JMSDF Logistics Interoperability and Integration Strategic Framework — would create opportunities for sharing best practices and procedural updates among the four partners, and build towards a more integrated maritime logistics capability.¹⁸² These swaps already occur in the context of Exercise Malabar¹⁸³ but should be considered for bilateral operations and activities as well. While the basics of seaborne resupply are likely the same (or very similar), creating connections and mutual understanding among this community will help to generate the trust and “muscle memory” among Quad personnel that can be relied upon in times of need. This could be as simple as a single person serving in an observer role, or something more sophisticated like an embarked helicopter and flight crew from one Quad country on another’s vessel. Such arrangements may begin as an exercise capability but should be matured into an operational one as combined capacity increases.

Defence industry and technology cooperation

Strategic rationale

To effectively underwrite a collective maritime defence agenda, the Quad needs to significantly expand cooperation in the development, manufacture and sustainment of interoperable weapons systems and defence materiel. This is a critical component of any effort to find common solutions to shared operational challenges. Specifically, Quad countries should develop affordable options for producing munitions and other critical mission items and, where possible, pursue co-developed projects with direct application in the maritime domain.

All Quad countries face acute challenges in building and maintaining adequate stocks of attritable lethal and non-lethal defence items. US stockpiles and production lines for critical mission items, like torpedoes and sonobuoys, have been under stress for years, well before the war in Ukraine put a spotlight on the pressure points across its wider industrial ecosystem.¹⁸⁴ This increasingly dire situation has produced nascent efforts to integrate trusted allies into the US defence industrial base more deeply, above all to address yawning production shortfalls and supply bottlenecks for precision-guided munitions.¹⁸⁵ Australia’s reliance on US-based manufacturing for these items has left it particularly vulnerable, with alliance discussions about localising munitions production in-country progressing in fits and starts.¹⁸⁶ Top Japanese officials have highlighted their country’s insufficient stockpiles of maritime-oriented munitions and spare parts as a critical weakness.¹⁸⁷ Recent confirmation by Indian officials of Russia’s inability to honour key arms delivery commitments has highlighted the growing vulnerability of that relationship for New Delhi, particularly when it comes to replenishing munitions stockpiles.¹⁸⁸ Indeed, many Indian naval officers see a growing need to collaborate with Quad partners to buttress India’s advanced and asymmetric maritime capabilities to prevent Chinese adventurism in the Indian Ocean.¹⁸⁹

A Submarine Launched Countermeasure Emulator vehicle is embarked onto HMAS Collins at HMAS StirlingSource: Australian Department of Defence

It is in this context the Quad should explore networked options to build more resilient defence supply chains for common munitions and expendables, as well as targeted co-development projects, to support shared operational requirements. To be clear, the Quad countries’ maritime security inventories and force requirements will never mirror one another, nor will their defence industrial bases ever be entirely fused. But with a narrow focus on building interoperable capabilities to support shared requirements in the maritime domain, such as maritime domain awareness and anti-submarine warfare, there are realistic opportunities for the Quad to collaborate more closely on defence industrial inputs. Significant interoperability is already enabled by common platforms like the P-8 Poseidon aircraft and MH-60R Seahawk helicopter and their Japanese equivalents (see Figure 5), the MQ-9B Sea Guardian UAV, and the sale of other advanced hardware, including Australian and Japanese naval radars to the United States and India, respectively.¹⁹⁰ These developments provide a solid basis for deepening targeted defence industrial cooperation. This should include assessing joint force requirements for expendable, non-exquisite maritime capabilities like missiles, sonobuoys, unmanned systems and other items, and exploring ways to leverage one another’s comparative strengths to develop and strengthen common defence supply chains for these assets.

State of play

The Quad has already sought to deepen cooperation on technological and industrial supply chain issues relevant to defence. For instance, the Quad countries established a Critical and Emerging Technologies Working Group in 2021 and have mapped “collective capacity and vulnerabilities in global semiconductor supply chains” to bolster the resilience of the regional microchip industry.¹⁹¹ Though nominally focused on commercial challenges, senior officials recognise the military implications of such cooperation, particularly with respect to the development of next-generation radars and munitions.¹⁹² Nevertheless, this sort of cooperation remains one step removed from an explicit focus on defence industrial and technological inputs into a collective maritime security agenda.

Defence-focused industrial cooperation is an increasingly prominent feature of the Quad’s constituent bilaterals, with an emphasis on expanding maritime defence trade and co-production of key capabilities, such as advanced radars, unmanned undersea capabilities, underwater domain awareness and communications technologies, and long-range naval munitions.¹⁹³ The United States in particular has sought to advance defence industrial initiatives with each Quad partner.¹⁹⁴ Under a recently signed Memorandum of Understanding, Japan and the United States will pursue co-development projects in high-power microwaves, autonomous systems and counter-hypersonics.¹⁹⁵ Australia and the United States are seeking to deepen collaboration on in-theatre munitions production through the former’s Guided Weapons and Explosive Ordinance (GWEO) enterprise and on advanced naval systems through AUKUS.¹⁹⁶ The 2023 US-India initiative on Critical and Emerging Technology (iCET) seeks to foster long-term collaboration on munitions and other capabilities with “maritime security and intelligence surveillance reconnaissance (ISR) operational use cases.”¹⁹⁷

These efforts, however, are taking place against a legacy of mixed success. The United States and Australia are far and away the most successful Quad dyad when it comes to co-development and co-production, including on munitions like the Mk-48 torpedo and precision strike missile.¹⁹⁸ Yet US restrictions on technology transfer, information sharing and export controls have impeded longstanding efforts to build an Australian manufacturing base for precision-guided munitions, including through the expansion of the US National Technology and Industrial Base and GWEO.¹⁹⁹ By contrast, the United States and Japan have only fielded one successful joint project, the SM-3 interceptor, since 1980.²⁰⁰ Reservations over technology-sharing have prevented the United States from using the 2012 Defence Technology and Trade Initiative (DTTI) to transfer advanced defence technologies to India and obstructed efforts to onshore production for legacy systems like the Javelin anti-tank missile.²⁰¹ Other intra-Quad efforts have fared little better. Despite developing a comprehensive list of dual-use technologies of mutual interest, India and Japan have progressed only one co-development project (for unmanned ground systems) since establishing a Joint Working Group on Defence Equipment and Technology Cooperation in 2015.²⁰² Australia-Japan cooperation on undersea mapping and hydrodynamics technologies has moved similarly slowly,²⁰³ while defence industry cooperation has been largely marginalised in the Australia-India relationship until very recently.²⁰⁴

There is a growing awareness among the four countries of the need to collaborate with trusted partners on these challenges.

There is a growing awareness among the four countries of the need to collaborate with trusted partners on these challenges. Yet advancing defence industrial collaboration within the Quad will require creative solutions to longstanding obstacles, including a willingness to revisit restrictions on technical information and intellectual property, a greater tolerance for accepting the risk that comes with industrial interdependencies and force structure collaboration, and an effort to foster the trust required to share insights on one another’s supply chain vulnerabilities.²⁰⁵

Fortunately, there are signs to suggest that progress can be made on targeted projects of mutual interest. US firms have recently revived their dormant interest in developing co-production facilities for Javelin missiles with India through DTTI, while the intellectual property rights for a new US-India air-launched ISR UAV co-development will be jointly owned for the first time.²⁰⁶ Senior Australian and US defence officials are committed to addressing the thorny barriers to cooperation through AUKUS and GWEO,²⁰⁷ with the agreement to start building LRASM components in Australia viewed by some as a test case that will demonstrate the viability of localising production for entire systems and other precision-guided weapons.²⁰⁸ In an effort to advance bilateral defence trade and co-production, Japan and India have recently established an initiative to educate one another’s defence and industrial sectors on their respective defence procurement arrangements.²⁰⁹ Taken together, such developments suggest a willingness by Quad partners to find incremental solutions to longstanding problems in the interest of achieving progress. Even if these measures fall short of completely resolving complex systemic issues, this should not prevent the Quad from exploring new opportunities for cooperation that are “good enough” to underwrite a more collective maritime security agenda.

Recommendations

1. Establish a Quad Initiative for Maritime Security Capabilities within the existing Maritime Security Working Group to assess individual and collective maritime defence requirements, identify opportunities for and barriers to collaboration, and advance cooperation on interoperable maritime capabilities.
   
   The four countries should create a Quad Initiative for Maritime Security Capabilities to assess individual needs and develop collective solutions to shared maritime defence capability requirements. This initiative could be modelled on the AUKUS Joint Steering Group (established to drive implementation of the agreed defence industrial priorities and overcome barriers to cooperation)²¹⁰ or the Ukraine Defense Contact Group (established to jointly assess requirements and share inventory information in the interests of delivering military aid to Ukraine).²¹¹ The Quad should use this initiative to assess and advance collective requirements for targeted, mission-driven cooperation on maritime-relevant defence industrial projects. It should develop a catalogue of interoperable (or potentially interoperable) maritime capabilities produced across the four countries as a means of mapping respective strengths and weaknesses and identifying shared gaps and priorities. It should explicitly focus on interoperable capabilities that could support coordinated or collective operations in intelligence, surveillance, and reconnaissance, maritime domain awareness, anti-submarine warfare, chokepoint security and maritime strike.²¹² To this end, officials from all four countries could draft lists of dual-use and military technologies which governments are willing to make available for co-development and collaboration among Quad partners.²¹³ Relatedly, Quad countries should also collaborate on “shopping lists” for key maritime capabilities or mission items to meet collective and individual requirements.
2. Launch a defence supply chain mapping project with an initial focus on critical lethal and non-lethal items, like sonobuoys and long-range anti-ship missiles, used across common platforms such as the P-8 maritime patrol aircraft.
   
   Under this Initiative, the Quad should undertake a defence supply chain mapping project, modelled on that already conducted for semiconductors, for select defence supply chains relevant to maritime defence operations.²¹⁴ In the first instance, this might focus on inexpensive but highly expendable items used by common platforms central to Quad countries’ ASW and MDA operations, such as the sonobuoys and torpedoes used by the P-8/P-1 aircraft and MH-60/SH-60K helicopter. Preliminary studies suggest that US sonobuoy supply chains are over-concentrated and under significant stress,²¹⁵ owing to industrial bottlenecks and “unplanned operational expenditures” to counter the increasingly high tempo of Chinese and Russian submarine activity.²¹⁶ Worse, Quad partners like Australia and India are “disproportionately vulnerable” to disruptions or shortages in sonobuoy and torpedo supply given that production is based entirely in the United States.²¹⁷ Outsourcing second-source production to Quad partners would help to relieve overstretched supply chains and provide ready sources of resupply in-theatre for all four.
   
   The same approach should be applied to specific classes of naval precision-guided munitions for which demand among the Quad is increasing. The United States has moved to increase domestic production capacity for key maritime munitions, including doubling long-range anti-ship missiles (LRASM) production, tripling Mk48 torpedoes production, and boosting Tomahawk cruise missiles production sixfold.²¹⁸ Japan plans to purchase 400 Tomahawk missiles between now and 2027 to cover ongoing range extension works to its own Type-12 anti-ship missile.²¹⁹ Australia will purchase 220 Tomahawks as part of a wider package to enhance coverage of its maritime approaches.²²⁰ However, US production capacity for these and other munitions is highly unlikely to be able to provide for its own growing requirements as well as those of Australia and Japan.²²¹ India has sought to expand its own domestic production capacity for anti-ship missiles to deploy more of these systems along strategic waterways in the Eastern Indian Ocean but faces capital investment and technological challenges to realising this agenda.²²²
3. Explore collective supply chain innovations for in-demand capabilities by emulating the Quad Vaccine Initiative model, including its joint financing and distributed production arrangements.
   
   These mapping projects should be used to drive collective supply chain innovations, potentially adopting a joint delivery approach similar to the Quad Vaccine Initiative where each country plays to its competitive advantages.²²³ For instance, US technology could be coupled with Indian industrial heft and Japanese financing to stand up additional sonobuoy and munitions production facilities in Australia, Japan and India, with collective supply arrangements built into these agreements. Exploring options to distribute production across the Quad countries should be designed to dovetail with new and emerging initiatives that aim to develop shared logistics, sustainment and maintenance capabilities in Australia and India, respectively, to support the partners’ maritime aircraft and surface vessels.²²⁴
4. Establish formal training programs and embed arrangements to train Quad officials and industry representatives on one another’s defence procurement systems and processes, building on the model being developed by Japan’s Acquisition, Technology, and Logistics Agency (ATLA) for Indian counterparts.
   
   To facilitate this agenda, Quad countries should establish their own formal training programs for foreign defence officials and industry representatives to build awareness around their respective defence procurement systems and processes. Developing this institutional knowledge will be critical if the four countries are to successfully navigate each other’s acquisition, export control, technology release and information-sharing arrangements. Such efforts are already underway in some Quad dyads. For instance, Japan’s Acquisition, Technology and Logistics Agency has committed to conducting surveys of Japanese companies seeking to do business with Indian counterparts and financing training modules on both governments’ defence procurement procedures for industry.²²⁵ Similar proposals have been made in the context of US-Australia cooperation as a means of overcoming barriers to defence industrial integration.²²⁶ Such programs do not have to be badged as Quad activities and could be extended to other priority partners such as France, South Korea and the United Kingdom. These programs should be designed to evolve into official exchanges or embed programs between Quad countries’ defence departments and regulatory agencies to consolidate institutional knowledge and create pathways for fast-tracking collaborative projects. Such an initiative would complement existing liaison or embed programs at the foreign ministry, military, intelligence and regional command levels between Australia, Japan and the United States.

Coordinated maritime capacity building

Strategic rationale

As part of its mission to support sovereignty, territorial integrity, and freedom of navigation and overflight, the Quad must play a larger and more coordinated role in bolstering the maritime security capabilities of its Indo-Pacific partners. This is especially urgent in littoral Southeast Asia. Over the last decade, China has become increasingly aggressive in deploying its naval, coast guard and militia forces to coerce Southeast Asian nations over disputed maritime resources, waterways, and territorial interests. Spurred on by its construction of a network of artificial military islands, Chinese forces now exercise a persistent strategic presence throughout the South China Sea.²²⁷ In this context, regional states need continued support in countering malign behaviour at sea such as illegal, unreported and unregulated fishing (IUUF), transnational crime and environmental degradation. Absent more robust efforts by ASEAN nations to counter this new status quo, China will continue to conduct maritime grey zone activities with near impunity, extend its anti-access/area denial capabilities, and succeed in complicating the ability of the United States or other security partners to assist Southeast Asian nations in the event of a crisis.²²⁸

Quad countries have provided significant support to Southeast Asian nations in developing their maritime security capacity, particularly in the maritime domain awareness space. Providing the Quad’s regional partners with the technical means and skillsets to know what is happening in their territorial waters and exclusive economic zones (EEZs) meets regional needs for maritime law enforcement and provides insight into Chinese actions that subvert regional states’ sovereignty.²²⁹ However, existing capacity- and capability-building efforts by Quad countries have suffered from a lack of coordination, often leading to more capacity assistance than recipients can absorb in certain areas and duplication of effort in some instances.²³⁰

Flight Lieutenant Dylan Smith explains characteristics of the P-3C Orion with visiting Indonesian Air Force MARPAT representatives during the Exercise Albatross AUSINDO Initial Planning ConferenceSource: Australian Department of Defence

To help Southeast Asian nations better safeguard their own interests, the Quad should pursue a coordinated approach to maritime security capacity building. Its dual objectives should involve consolidating duplicative lines of effort and developing a combined strategy that addresses regional needs in a comprehensive manner and with the inclusion of all four partners. The Quad should focus its efforts on Indonesia, the Philippines and Vietnam: key partners with complementary, albeit far from aligned, strategic preferences that have expressed an interest in working more closely with Quad nations to meet their capability needs.²³¹ The Quad’s Indo-Pacific Partnership for Maritime Domain Awareness (IPMDA), set up in May 2022 to provide regional partners with a more comprehensive operational picture of their maritime environments, is a solid foundation for this agenda.²³² Providing Southeast Asian partners with the required tools, ranging from constabulary assets to military platforms, to act on this information in timely and effective ways is critical. While all four Quad partners have developed individual methods and mechanisms for this task, their efforts continue to lack coherence.²³³ As such, developing a coordinated strategy that aims to maximise the operational effectiveness of recipients’ maritime surveillance and security capabilities could be a “force multiplier” for the Quad’s frontline Southeast Asian partners.²³⁴

State of play

Quad countries have traditionally invested in regional maritime capacity building separately, pursuing a variety of largely bilateral capability transfers and training programs. Through the 2015 Indo-Pacific Maritime Security Initiative, the United States has provided training, surveillance systems and other platforms to enhance the coast guard, navies, and maritime domain awareness capabilities of key Southeast Asian partners, above all Indonesia, Malaysia, the Philippines and Vietnam.²³⁵ Japan has delivered coast guard vessels, training aircraft, maintenance assistance, and information-sharing capabilities to help Southeast Asian nations counter Chinese grey zone activity,²³⁶ standing up a new Official Security Assistance program in 2023 and pursuing legal reforms to make the transfer of defence equipment to regional nations more streamlined.²³⁷ While India is primarily focused on the Indian Ocean region, it too has increased capacity building efforts in Southeast Asia, particularly in Vietnam, where it has extended US$1 billion in credit for arms purchases since 2016 and delivered 12 high-speed coast guard vessels in 2022.²³⁸ Australia’s capacity building efforts in Southeast Asia have paled in comparison with Quad counterparts and lag behind its Pacific Step-Up. Canberra has nevertheless provided training programs and donated landing or patrol craft and maritime UAVs to Indonesia and the Philippines, with expectations of greater regional security assistance in the pipeline.²³⁹

All four Quad partners have significant regional defence sales portfolios which must also be accounted for in regional capacity building. Japan has offered to sell destroyers to Indonesia and is finalising export deals for advanced air and naval radars to the Philippines.²⁴⁰ India has secured or pursued sales of land- and ship-based BrahMos cruise missiles to Indonesia, the Philippines and Vietnam.²⁴¹ The United States has offered F-15 fighters and harpoon missiles to the Philippines, approved the sale of F-16 fighters to Indonesia, and is exploring the possibility of providing Vietnam with advanced drones and radars as it weans itself off Russian arms.²⁴² While Australia is not a traditional player in the regional arms trade, it offered the Philippines 12 offshore patrol vessels in 2022, in a proposal that was ultimately rebuffed.²⁴³

Minister for Foreign Affairs Penny Wong meets with Philippines Secretary for Foreign Affairs Enrique Manalo in Manila in May 2023. Minister Wong used the visit to announce a new maritime capacity-building package for the Philippines Coast Guard. Source: Department of Foreign Affairs and Trade

These and other high-end capability programs are needed to build the capacity of Southeast Asian partners. But without sufficient coordination, they risk exacerbating force integration challenges for militaries that are already grappling with limited budgets and interoperability issues posed by legacy hardware.²⁴⁴ Quad partners have, in fact, exacerbated these challenges by offering duplicative capability-building programs and training to the same partners. This includes, for instance, the transfer of three different classes of coast guard and patrol vessels to Vietnam by India, Japan and the United States.²⁴⁵ Even low-level training programs and English-language courses administered by the United States and Australia have been “fragmentary and disparate” owing to the lack of coordination.²⁴⁶ Put simply, while Quad countries individually agree on the need to bolster the capabilities of Southeast Asian partners, they rarely consult each other before advancing capacity building programs, with the default approach resembling one of “acting first, advising later.”²⁴⁷

Quad countries are alert to this problem. But they have exhibited only a fluctuating interest in better coordinating maritime capacity building efforts, with the issue continuing to register inconsistently across its different third-party relationships. Senior Australian, Japanese and American leaders have recently flagged expanding bilateral and trilateral cooperation on joint training, capacity building and transfers of defence equipment to Southeast Asian partners.²⁴⁸ These commitments, however, are far from new, having been first made in the early-to-mid 2010s before falling off the official agenda (with the exception of limited bilateral US-Japan collaboration on coast guard and MDA initiatives for the Philippines).²⁴⁹ Cooperative maritime capacity building aims have only recently appeared on the bilateral Australia-India and US-India agendas,²⁵⁰ and are still largely missing in the India-Japan case.

In any arrangement, care must be taken to support regional states in pursuit of their own priorities and allow them to remain outside of any dynamic that might bring them into conflict with Beijing. Capacity building aims should buttress regional sovereignty and support them in standing up to aggression in the maritime space, with the expectation and understanding that the region will continue to balance their relationships with China and the Quad states rather than side with one against the other. For this reason, capability building will likely continue to remain weighted heavily toward maritime law enforcement but will not exclude higher-end military cooperation.

Recommendations

1. Establish a Maritime Capacity Building Initiative (MCBI) to expand Quad efforts to strengthen the maritime security capabilities of key Southeast Asian partners and operate as a “clearing house” to align efforts, share information and eliminate duplicative programs.
   
   The Quad needs a Maritime Capacity Building Initiative (MCBI) to coordinate and expand its ad hoc efforts to strengthen the maritime security capabilities of key Southeast Asian partners. This could be housed within the Quad’s existing Maritime Security Working Group but will require the involvement of relevant defence officials, foreign affairs personnel, military officers and coast guard staff to be effective.²⁵¹ The MCBI would function as a “clearing house” for the Quad’s capacity building efforts, with a focus on: fostering shared maritime capacity building objectives; facilitating greater information-sharing on regional needs; conducting joint and combined needs-based assessments on recipients’ force requirements; promoting complimentary capability assistance programs; and deconflicting duplicative efforts. As with the IPMDA, this initiative could focus initially on a subset of Southeast Asian partners — Indonesia, the Philippines and Vietnam — with expansion to Indian Ocean and Pacific Islands partners to be considered in the future.
2. Co-design and co-administer coast guard training programs for Southeast Asian partners, with a view to establishing a Quad Coast Guard Working Group.
   
   Cooperation on coast guard training and capacity building programs through the MCBI would be a relatively easy place to start. This could build on already robust regional coast guard presence and training programs administered by Japan and the United States,²⁵² and emerging patterns of regional engagement by the Indian Coast Guard and Australian Border Force.²⁵³ Just as Japan and the United States co-administer training programs with the Philippines Coast Guard under the bilateral SAPPHIRE partnership,²⁵⁴ India and Japan could explore similar options with Vietnam, to which both countries have provided patrol vessels and other capacity building assistance.²⁵⁵ Developing synergies of this type would benefit the Quad’s Southeast Asian partners, with the aim of encouraging wider regional standardisation of best practices and procedures through joint training and exercises, and should also take into account ASEAN’s maritime security work plan and priorities.²⁵⁶ Where permissible, such programs should include standing invitations for non-participating Quad countries to send official observers in order to enhance a shared understanding of regional needs and capabilities and inform wider capacity building programs. Such an approach would help to amplify current Australian Border Force engagements in the region,²⁵⁷ potentially opening pathways for Offshore Patrol Vessel deployments to the region.²⁵⁸ If successful, such cooperation could eventually be formalised under a dedicated Quad Coast Guard Program.²⁵⁹
3. Set up an integrated working group within the MCBI to identify opportunities for Quad countries to provide complimentary platforms to Southeast Asian partners, with a focus on maritime domain awareness (MDA), intelligence, reconnaissance and surveillance (ISR), and patrol assets.
   
   The MCBI should aim to facilitate closer coordination on military capability assistance, with a focus on maritime domain awareness and law enforcement capabilities. An integrated working group could identify opportunities for Quad countries to provide complimentary platforms and defence services to key Southeast Asian partners, focusing on ISR and MDA systems such as unmanned aerial vehicles or advanced coastal radars that enable effective constabulary and military action at sea. Building increased capacity in key enabling capabilities, like real-time domain awareness, would also increase the operational utility of newly-acquired national capabilities such as ships, fighters and cruise missiles.²⁶⁰ Recent sales or transfers of US and Japanese domain awareness capabilities and Indian naval strike missiles to the Philippines, though uncoordinated, provide one example of what this cooperation could look like with other partners, like Vietnam or Indonesia, interested in acquiring similar combinations of assets — with the caveat that an integrated solution would require significantly more coordination from the Quad partners themselves.²⁶¹ At its most foundational levels, even strictly bilateral security assistance should at least be evaluated for its ability to be integrated with existing or pending equipment deliveries from the other three partners.
4. Scope options to collectively provide joint force integration assistance programs that support Southeast Asian nations to achieve higher levels of interoperability between their legacy, often Russian-sourced forces, and newly-acquired Western capabilities from multiple suppliers.
   
   Relatedly, the MCBI should also scope possibilities for collectively providing joint force integration assistance programs to Southeast Asian nations. At present, all four Quad countries (as well as major suppliers like South Korea and France) are working to support military modernisation efforts in Indonesia, the Philippines and Vietnam,²⁶² with Manila emerging as the Quad’s unofficial priority.²⁶³ Yet, integrating military platforms and technical assistance from multiple well-meaning partners is not easy for recipients.²⁶⁴ By assisting defence suppliers and Southeast Asian recipients to identify, address and pre-empt force integration challenges, the MCBI could improve the net value of security assistance. Given its own challenges with integrating capabilities domestically, India has a particularly important role to play here, providing valuable insights for partners seeking to integrate US- or Japanese-built MDA systems with legacy Soviet hardware or systems like BrahMos co-developed with Russia.
5. Undertake a pilot program to collectively refurbish existing Quad capabilities for transfer to Southeast Asian partners.
   
   Finally, Quad countries should also explore collective programs for refurbishing existing maritime domain awareness systems, with each contributing platforms, hardware, training or funding based on individual capacity. The Quad, for example, could work together to refurbish and transfer excess coast guard patrol vessels to Southeast Asian partners. Rather than being solely administered by a single donor, coordinated efforts by the Quad could help to ensure timely and effective delivery and would augment the grouping’s ongoing efforts to provide public security goods that enhance regional stability.