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The debate over how best to deter China in the western Pacific has reached a new level of ambition. Ely Ratner, a former senior defense official in the Biden administration, proposed a “Pacific Defense Pact” — a legally binding multilateral treaty among the United States, Japan, Australia, and the Philippines. This reflects serious concerns over China’s rise and its potential future use of force along the first island chain. The underlying diagnosis is sound: Existing U.S. alliances in the region lack an integrated command and control structure and the collective responsiveness required to credibly deter China in a high-intensity conflict. But the proposed remedy deserves careful scrutiny. A formal pact, however well-intentioned, carries risks that its advocates have not fully reckoned with: theoretical risks rooted in the logic of deterrence, and practical risks embedded in the realities of alliance politics.
The strategic logic behind the Pacific Defense Pact is straightforward: Deterrence requires credibility, and credibility requires joint combat capabilities based on a legal structure. Without a common command and control architecture and binding mutual defense commitments, U.S. allies cannot convincingly signal that they will respond collectively to Chinese aggression. To fix Chinese General Secretary Xi Jinping’s calculus — to ensure that he concludes “today is not the day” to move against Taiwan or the East and South China Seas — Washington and its partners must formalize their commitments and deepen their operational coordination.
The problems begin when the proposal meets political and strategic reality. The four prospective members hold markedly divergent threat perceptions on the China threat. A legally binding alliance would create a “commitment hazard” — the risk that allies are locked into obligations they may not honor. Furthermore, the very act of forming the pact risks alienating nations unprepared to join, thereby fraying the flexible “latticework” of efficiently exclusive minilateral frameworks that Washington painstakingly assembled over the past decade — bilateral, trilateral, and quadrilateral arrangements calibrated to what each partner could actually commit to.
The goal of “deeper institutionalization” — especially in areas such as force posture, operational planning, and command and control — is the logical and effective one. The vehicle for getting there is not. The case for a formal pact has two significant lacunae: one rooted in deterrence theory, the other in the practical question of where allied resources are best spent.
The psychological logic of deterrence does not end at “not today.” The sentence that follows is equally consequential: “But tomorrow may be better.” This is the central insight of what scholars variously call prospect theory and peak power theory, and it is an insight that the pact proposal has not adequately absorbed.
Dale Copeland’s examination of Japan’s decision to attack Pearl Harbor offers an instructive historical parallel. Japan’s leadership did not strike in December 1941 from a position of confidence. They struck because they had concluded that time was running against them — that American industrial mobilization and the oil embargo would progressively erode Japan’s relative military position until war became unwinnable. In June 1941, the “Outline of Measures Against the South,” agreed between the Imperial Japanese Army and Navy stipulated that Japan would use force “if its very existence was threatened by the Anglo-American-Dutch embargo,” or if the encirclement of Japan intensified to a degree “no longer tolerable for national defense.” The decision for war, in other words, was driven by a closing window, not an opening one.
Michael Beckley and Hal Brands have formalized this logic in their peak power theory: Rising powers become most dangerous not at the height of their ascent, but at the inflection point when they perceive that their relative advantage has begun to erode. Applied to China in 2026, this framework yields an uncomfortable implication for the pact proposal. A Pacific Defense Pact would not merely signal resolve. It would alter Beijing’s assessment of its future strategic position. Since alliance formation requires time — months or years of drafting, negotiation, and ratification — Chinese planners might conclude that acting before the pact enters into force is preferable to waiting until military options are permanently foreclosed. The prospect of a closing window could stimulate, rather than constrain, Chinese adventurism. A formal pact designed to strengthen deterrence could, paradoxically, shorten the fuse.
This is not an argument against alliance deepening in principle. It is an argument that the sequencing and signaling of institutional change matter enormously. A pact designed to deter could, ironically, catalyze the very conflict it seeks to prevent.
While there is — in theory — a narrow path through this dilemma, it is implausible in the current climate. For instance, Washington could draft treaty language privately, then transmit the text simultaneously to prospective allies and to Beijing — accompanied by a presidential communication reassuring that the document will not be signed so long as China refrains from the use of force. This approach would preserve the pact’s coercive leverage while removing Beijing’s incentive to act during the negotiating window, i.e., not making another Hull Note.
However, should it become apparent that the president is directing allies to shoulder increased burdens and consider formal alliance proposals while simultaneously conducting backroom deals with Beijing, U.S. credibility within the alliance will decline further. Its credentials have already been diminished by the use of military force in the Middle East and Latin America, with some even viewing China as a lesser evil. Given this political reality, it is highly questionable whether the U.S. can effectively draft alliance text or communicate appropriately with both allies and adversaries.
The second objection is more prosaic but no less consequential. The diplomatic and institutional bandwidth consumed by negotiating, ratifying, and implementing a new multilateral treaty is not free. Beyond Ken Jimbo’s concern that a formal pact would externalize non-participating nations, it is necessary to ask how much marginal benefit the legal architecture actually adds to security cooperation that is already advancing. The relevant question is one of resource allocation: Among the three pillars of credible deterrence — legal foundation, combined command and control, and joint operational capability — where does investment yield the greatest return?
The recent trend suggests the answer for regional policymakers is: first, operational capability, and then command and control, not legal architecture. The United States, Japan, and Australia concluded a trilateral information-sharing arrangement in 2016 and a naval logistics agreement enabling mutual refueling and resupply at sea in 2025. Japan’s reciprocal access agreement with Australia entered into force in 2023, and a comparable agreement with the Philippines followed in 2025. For potential combined command, Australia has participated in Japan–U.S. command post exercises, including Keen Edge and Yama Sakura, since 2023. The three nations are preparing a trilateral fighter exercise in Australia for Exercise Southern Cross in July 2026 and live-fire air and missile defense exercises in 2027. The Australian-U.S. relationship has progressed from a Marine rotational deployment to Darwin — first requested in 2012 — to the current deployment of nuclear-powered submarines to Western Australia and the anticipated operation of Australian-crewed submarines under the Australian- U.K.-U.S. arrangement.
None of this yet constitutes the aforementioned “deeper institutionalization.” But it demonstrates that the allied governments are methodically constructing the operational foundations of integration through a bottom-up approach — and, crucially, doing so without triggering the desperation dynamic in Beijing that a headline-generating treaty negotiation might provoke. Although the present situation may always seem inadequate to us living here and now, we must not forget that it may well be following the optimal course. The critical next step is not the formalization of mutual defense commitments but the further integration of command and control.
History offers a clear answer to the question of whether meaningful command integration can be achieved without a formal treaty: It can. The command structures that prosecuted Allied operations in the Pacific during World War II were not the product of a peacetime treaty. The Southwest Pacific Area, established in March 1942 under Gen. Douglas MacArthur, integrated American and Australian forces under a single operational headquarters despite the absence of a formal mutual defense treaty between Washington and Canberra. As Peter Dean has scrutinized, the command arrangement — which emerged from urgent operational requirements — put all Australian combat units in theater under MacArthur’s command while Australian national command authority remained nominally intact. The result was a functional combined command without a predated formal alliance pact.
The contrasting case is equally instructive. The American-British-Dutch-Australian Command, created in January 1942 to coordinate the defense of Southeast Asia, collapsed within weeks under Japanese pressure. Yet its failure stemmed not from the absence of a legal framework, but from mismatched strategic priorities among its members and — critically — the absence of joint and combined unity of command. Another failure was the Southeast Asia Treaty Organization, which explicitly included mutual defense obligations that nonetheless collapsed for political reasons and the lack of a combined command structure. One lesson drawn from these concerns is the shortcomings of a hastily assembled, superficially coherent combined command, versus the practical necessity of placing allied combat units under the command structure of a major power, dictated by the demands of actual warfare.
The question of peacetime command integration carries an additional political dimension that the Pacific Defense Pact proposal leaves underexplored. Integrated command structures established before a conflict distribute command positions across alliance members, as NATO has done through Supreme Headquarters Allied Powers Europe — where smaller allies occupy several key operational, not combat, roles that reflect negotiated political agreements. For smaller allies, this represents a genuine institutional achievement: influence secured before a crisis that would otherwise foreclose it.
Yet the NATO model also exposes a structural asymmetry that any Indo-Pacific equivalent would inherit. As Skip Davis — a former NATO deputy assistant secretary general — has observed, the gap in senior leadership experience between the United States and its partners is qualitative, not merely quantitative: Theater-level command experience — the kind that matters most in a major power conflict — exists, at present, only within the American military.
In the Indo-Pacific, the only command with theater-level command experience and capabilities is the U.S. Indo-Pacific Command. Based on the historical pattern that alliance relationships tend to crystallize into operational command structures regardless of whether those relationships are codified in treaty language, Indo-Pacific Command should command not only U.S. combat forces but also allied forces out of necessity. The disproportion in military capability makes this near-certain. A peacetime integrated command structure created through the multilateral formalization of defense treaties would require Washington to engage in politically sensitive negotiations over hierarchies that wartime necessity would likely override regardless. It is therefore rational, from an American standpoint, to advance interoperability, force posture alignment, and logistical complementarity — the real determinants of wartime effectiveness — while deferring the politically contentious questions of formal command hierarchy.
The second Trump administration also makes formal treaty-making unlikely. An administration that has treated NATO burden sharing as a grievance and European allies as counterparties is poorly positioned to champion a new binding multilateral pact in the Indo-Pacific. In essence, the administration’s instinct is to treat allied capacity as something to exploit rather than integrate.
The implication for smaller allies is counterintuitive but strategically important. Given the aforementioned benefits, Japan, Australia, and the Philippines should themselves be the demanders of the further integration of command and control with the U.S. Indo-Pacific Command, even at some political cost. The Trump administration’s transactional approach to alliances generates understandable anxiety, but it does not alter the underlying military reality: Allies with capable, interoperable forces and personnel embedded in American command structures will exercise far greater operational influence in a crisis than allies who kept their distance out of political discomfort.
It does not mean allies are ready to shape terms proactively due to the divergent perception on the gravity of the situation amongst the allies. I was present at Ratner’s lecture in Sydney. While I am critical of Ratner’s proposal, I fully concur with his views on joint operational capabilities and the integration of command structures. From my perspective, I must say the questions posed by the audience and moderators felt somewhat off the mark, using the outrageous shortcomings of the Trump administration for sidestepping the fundamentally crucial discussion of the potential need for military integration with the United States and its allies. As Ratner himself reflects his Australia visit, leaving hard questions unsaid is “no longer viable,” yet Australia, at the very least, does not seem to grasp the gravity of this.
Certainly, President Donald Trump’s disregard for international law, symbolized by his wars in the Middle East and the operation against Venezuela, makes a multilateral defense treaty with the United States extremely difficult for allied leaders. Cooperation through minilateral arrangements like Squad has been justified precisely to maintain a rules-based order. In this context, investing political capital to pursue de jure integration with the U.S. military carries the risk of undermining the political foundations even of pro-American administrations like Japan’s Takaichi government or the Marcos regime in the Philippines. Trump’s war on Iran reminded all U.S. allies of the significance of “fear of entrapment.”
This is precisely why a bottom-up approach becomes critically important. Specifically, this entails combined military training (particularly the substantive integration of command and control systems within contingency planning), agreements to streamline relations between military authorities, and defense industry cooperation to enhance interoperability.
The Pacific Defense Treaty proposal and an Asian NATO idea have challenged the entrenched assumption that a multilateral alliance in Asia is structurally impossible. While such aspiration for deeper institutional integration is correct in principle, they underappreciate the historical lesson.
What the United States and its allies should pursue instead is a quieter but more durable agenda: de facto integration of command and control. Last year, Japan created a new unified military headquarters — the Joint Operations Command — to coordinate its army, navy, and air force under a single chain of command. Simultaneously, the United States decided to strengthen the command and control function of U.S. Forces Japan to smooth the coordination with the Japan Self-Defense Forces. However, the two countries still operate through separate command structures rather than a truly integrated one, risking delaying effective bilateral operations where real-time coordination, including joint targeting and strikes, is most critical. Practical steps toward genuine integration include: progressive sophistication of command post exercises that realistically simulate major-power conflict, live-fire air and missile defense exercises, and joint capacity building of the Philippines armed forces. The destination for all of this is what I call a “(South)West Pacific Command 2.0” — an integrated Allied operational headquarters designed for the specific strategic geography and political constraints of the contemporary Indo-Pacific.
Japan’s attack on Pearl Harbor was not an expression of Japanese confidence. It was the product of desperation — of a leadership that concluded, rightly or wrongly, that time had run out and that a closing window demanded immediate action. The lesson for deterrence strategy in 2026 is not that strength is counterproductive. It is that how strength is assembled, communicated, and sequenced matters enormously. A treaty that Beijing reads as permanently foreclosing its strategic options could compress the timeline for conflict rather than extend it. Quietly and steadily building the command structures, interoperability standards, and operational habits that would make allied resistance genuinely overwhelming is the path toward the credible deterrence aspired by the Pacific Defense Pact, and the one that leads away from Pearl Harbor rather than toward it.
Ryosuke Hanada is a member of the sessional teaching staff at the School of International Studies, Macquarie University. His latest publication is “‘Minilateralism: A New Page for Indo-Pacific IR Lexicon” in the Pacific Review. He has participated in several fellowship programs across the Indo-Pacific — including the German Marshall Fund, the Center for Strategic and International Studies, the Perth USAsia Centre, and Observer Research Foundation — and published in the Pacific Review, Lowy Interpreter, ASPI Strategist, East Asia Forum, and the Diplomat.
Image: Lance Cpl. Christine Phelps via DVIDS
