The emergence of the “Squad” alongside the Quad reflects a changing security landscape in the Indo-Pacific, wherein regional cooperation is being shaped by nontraditional security challenges and the imperative of military deterrence. The defense ministers’ meeting of the Squad – the United States, Japan, Australia and the Philippines – on the sidelines of the 13th ASEAN Defense Ministers’ Meeting-Plus (ADMM-Plus) in Cebu, Philippines on October 28 underscored this emerging trend. The meeting also took place alongside separate engagements involving the Quad partners – the United States, Japan, Australia, and India – highlighting how overlapping partnerships are focusing on distinct strategic purposes. 

The Squad showcases the operational dimension of Indo-Pacific security cooperation. Its significance lies in strengthening defense coordination among the U.S. and its allies – all countries with an immediate strategic stake in the western Pacific and the South China Sea. At the meeting in Cebu, the four ministers agreed to advance defense cooperation through consultations, joint military exercises, and other initiatives. Japan’s Ministry of Defense described these efforts as contributing to regional peace and stability. 

Australia’s Defense Minister Richard Marles also indicated that the discussion covered operational concepts and closer coordination among defense policy experts. These developments suggest that the Squad is moving toward more practical forms of military coordination, such as interoperability and joint exercises, that can strengthen the ability of participating countries to respond collectively to contingencies. 

The Philippines’ geographical position shapes the Squad’s strategic importance. As a claimant state in the South China Sea and a U.S. treaty ally, the Philippines occupies a crucial position along the First Island Chain. Hence, greater cooperation with Japan and Australia gives Manila additional strategic partnerships, while allowing Washington to strengthen its regional posture through a network of capable partners. The grouping could therefore contribute to deterrence by raising the potential costs of coercive actions and demonstrating that challenges to regional security may also elicit a coordinated response. The Squad’s contribution to regional peace would depend on whether its enhanced capabilities are accompanied by restraint, transparency and adherence to international law. 

On the other hand, although strategic coordination and maritime security remain important, Quad cooperation has also focused on nontraditional security challenges and the provision of regional public goods. These include humanitarian assistance and disaster relief, maritime domain awareness, critical and emerging technologies, health security, and resilient supply chains. This broader agenda gives the Quad a distinctive role in the Indo-Pacific. It brings together four countries – including India, which is not a U.S. treaty ally – to address shared regional challenges through practical cooperation and coordinated initiatives. The Quad’s approach is also particularly pertinent to Southeast Asia, where countries seek stronger maritime capabilities and economic resilience without wishing to become aligned with competing military blocs.

The Quad and the Squad therefore address different and overlapping dimensions of the regional security environment. While the Quad contributes to resilience and functional cooperation, the Squad is more directly oriented toward defense coordination and deterrence in a strategically sensitive maritime theater. The simultaneous meetings by the Squad and Quad partners around the Cebu ADMM-Plus raises an important question: is the emergence of explicitly defense-oriented minilateral arrangements reducing the Quad’s strategic relevance?

The answer is no, although it reflects a growing differentiation in the functions of Indo-Pacific partnerships. The Quad’s focus on nontraditional security cooperation should not be mistaken for an absence of strategic intent. Initiatives such as the Indo-Pacific Partnership for Maritime Domain Awareness demonstrate that its functional agenda can strengthen maritime surveillance, improve information-sharing, and help regional states respond to coercive activities. Nevertheless, the Quad has deliberately avoided becoming a conventional military alliance. The Squad, by contrast, provides a more focused platform for defense consultations, military exercises, and operational coordination among four countries with immediate security interests in the Western Pacific. 

Importantly, the Squad’s emergence does not establish a formal division of responsibilities between the two groupings, nor does it demonstrate that the Quad has been superseded. Rather, it illustrates how countries can pursue different levels of security cooperation through overlapping arrangements. The Quad’s broader agenda and the Squad’s more concentrated deterrence function can be complementary, even as their respective approaches reflect different strategic priorities.

For regional stability, the Squad presents both opportunities and risks. Enhanced interoperability, joint exercises, and defense consultations can strengthen deterrence and reassure countries concerned about coercion in contested maritime spaces. For the Philippines, the arrangement also provides a mechanism to deepen security partnerships and improve its ability to respond to regional contingencies. However, a regional order increasingly shaped by competing minilateral groupings risks intensifying strategic mistrust. China may interpret closer military coordination along the First Island Chain as an attempt to constrain its strategic options, potentially encouraging countermeasures and further militarization. Smaller Southeast Asian countries could also face greater pressure to navigate between competing security interests.

This makes the role of ASEAN and the ADMM-Plus particularly important. Unlike exclusive minilateral arrangements, ADMM-Plus brings ASEAN members together with eight dialogue partners, including India, China, Japan, the United States, and Australia, providing a forum for defense dialogue and practical cooperation. Its continued relevance lies in maintaining communication among competing powers while promoting cooperation on shared security challenges. 

In the same way, the Squad should be understood not as a replacement for the Quad but as an expression of the Indo-Pacific’s increasingly layered security architecture. The Quad seeks to strengthen regional resilience through a broad agenda of functional cooperation, while the Squad is developing a more direct role in military deterrence and maritime security. Both can contribute to regional stability, provided their activities reinforce international law, avoid unnecessary escalation and leave sufficient space for ASEAN-led diplomacy. The central challenge is not choosing between the two, but ensuring that stronger deterrence and wider regional cooperation remain complementary rather than contradictory.