The U.S.-Japanese-Philippine Trilateral Is Off-Balance


As geopolitical tensions rise in the Indo-Pacific, the U.S.-Japanese-Philippine security trilateral is rapidly emerging as a potentially pivotal defense arrangement. It has already garnered widespread attention and positive headlines in Washington and Tokyo, especially following the grouping’s inaugural meeting of national security advisors and first-ever trilateral Coast Guard exercise in June. Leaders on both sides of the Pacific have stated their desire for this arrangement to take a leading role on security matters in the East and South China Seas, collectivizing efforts to counter aggressive and illegal Chinese behavior.

However, as this trilateral continues to evolve, subtle cracks in Manila’s confidence are emerging. While many of these concerns have yet to appear in ongoing reporting and analysis of the U.S.-Japanese-Philippine trilateral, my field research over the past summer uncovered several points of frustration from Philippine defense leaders and commentators toward the arrangement. Specifically, there are growing concerns in Manila about the country’s ability to maintain an independent relationship with and strategy toward China, about Tokyo’s inclination to defer to Washington on security decisions, and about the unintended weakening of Japanese-Philippine bilateral security ties as a result of the trilateral’s solidification.

A balanced U.S.-Japanese-Philippine security trilateral can address collective security concerns in the East and South China Seas, as well as send a potent deterrent signal to China against any potential ambitions on Taiwan. As a result, getting the balance right matters. An unequally weighted trilateral relationship could, rather than bolstering a collective regional security posture, end up weakening its very premise. By promoting a reduction in overt transactionalism, an amplified role for Japan, and an appreciation for the trilateral’s value beyond Taiwan, all three countries can ensure that this new relationship can effectively meet the challenges facing the Indo-Pacific.



Old and New Concerns

Complaints of an overbearing or unreliable Washington are nothing new in Manila. For decades, mutual trust in the U.S.-Philippine defense alliance has ebbed and flowed. Relative high points, such as the signing of the 2014 Enhanced Defense Cooperation Agreement under President Benigno “Noynoy” Aquino, are often followed by relative low points, such as the drift away from U.S. cooperation during the years of President Rodrigo Duterte. Today, the alliance between the Philippines and the United States appears stronger than at any point in recent memory. Since taking office in June 2022, President Ferdinand Marcos Jr. has prioritized strengthening the U.S.-Philippine security relationship, a stance perhaps best evidenced by the February 2023 expansion and revival of the Enhanced Defense Cooperation Agreement, which allows the U.S. military access to nine Philippine military bases in close proximity to geopolitically critical flashpoints near Taiwan and the South China Sea.

Compared to the fluctuating U.S.-Philippine relationship, defense ties between Tokyo and Manila have been more consistent, though less deep-rooted. The relationship took a significant turn in 2012 after the Scarborough Shoal incident, which, beginning with Tokyo’s 2013 transfer of Coast Guard vessels, initiated a decade of continuous growth. Even during the Duterte era, Japan and the Philippines strengthened their defense bonds, with Japan increasing its port calls, enhancing bilateral capacity building, and transferring ships and equipment. This steady evolution has culminated in one of Manila’s most trusted security partnerships today.

Yet the extent of Manila’s current concerns became clear to me during my field research in July and August of 2023, during which I conducted a series of interviews with both current and former Philippine defense officials. These individuals were affiliated with prominent institutions including the National Security Council, the Department of Defense, and government-connected think tanks. While the insights garnered might predominantly represent elite opinions, it’s crucial to note that such perspectives are critical to understanding developing security issues like the U.S.-Japanese-Philippine trilateral. 

The first widely cited concern by Philippine defense leaders and experts toward the U.S.-Japanese-Philippine trilateral is its potential to limit Manila’s leverage in managing relations with Beijing. The bulk of these concerns come from a perception that America’s and Japan’s main motivations in expanding security relations with the Philippines revolve around Taiwan. The strategic position of the largest and most populated Philippine island of Luzon, located just 250 kilometers from Taiwan’s southern coast, makes the country an appealing partner and optimal location for basing in the event of a conflict. Yet not all leaders in Manila are ready to embrace an American- and Japanese-backed vision of an enhanced military posture in the northern Philippines.

To be sure, there are relevant and strategically critical motivations for the Philippines to be deeply concerned about any Chinese attempt to seize Taiwan, including the safety of the nearly 200,000 Philippine overseas workers on the island. For that reason, some politicians and defense leaders in the Philippines regularly advocate for a stronger stance on the issue. Nevertheless, the debate on a Philippine role in a war over Taiwan is far from settled. There is no consensus in Manila, however rough and ambiguous, on the topic in the manner of those apparently emerging today in Washington and even Tokyo. The closest Manila has come to a statement of military support for Taiwan were vague comments made by the Philippine ambassador to the United States in 2011 that Manila might allow Washington to use bases on its territory “if it is important for us, for our security.” Marcos himself has never shifted from a neutral stance on Taiwan and described his views in an interview: “I learned an African saying: When elephants fight, the only one that loses is the grass. We are the grass in this situation. We don’t want to get trampled.”

Some Philippine politicians have been promoting the idea that Washington is trying to entrap Manila in a future war over Taiwan. However implausible this may seem in Washington, U.S. policymakers should not expect this suspicion to vanish or shift toward more unambiguous support for Taiwan. The United States and Japan should instead acknowledge the intricate balance Manila strives to maintain in its foreign relations. Pushing too hard for a specific stance on Taiwan could strain the strategic partnership and compromise broader regional security goals.

Japan’s Muted Voice

The second concern is based on the perception in Manila that Tokyo tends to defer to Washington on security issues. As a result, Philippine defense leaders stressed to me that any disputes within the trilateral inevitably end with Japan backing American preferences, leaving the Philippines alone in its dissent. This can create a consistent “2+1” dynamic in trilateral forums where Manila is constantly outvoted.

This perception of Japanese deference is likely somewhat overstated, as Japan frequently engages with security partners in Southeast Asia on an independent basis from the United States. Indeed, as discussed above, its relationship with Manila is a prime example of this. Yet the concern has real historical and political roots that cannot be overlooked. Japan’s post–World War II alliance with the United States, coupled with the intricate dynamics of its defense-sensitive domestic politics, has led to a longstanding tendency to align with American preferences on security issues within the ruling Liberal Democratic Party. This alignment often involves Japanese politicians using the concept of Gaiatsu or “outside pressure” as a justification for pursuing otherwise controversial security reforms or actions, as seen in the deployment of Japan Self-Defense Forces to Iraq in 2004.

Consequently, from the perspective of the Philippines, Tokyo’s tendency toward deference can make the trilateral partnership with Japan and the United States seem even more American-dominated than its bilateral relationship with Washington. As a result, increasing alignment on security goals between Washington and Tokyo can appear more constraining than reassuring to Manila as trilateral ties deepen.

Trading a Bilateral for a Trilateral?

Finally, interviews with multiple defense leaders and experts in Manila revealed a clear displeasure with the possibility that an expanding U.S.-Japanese-Philippine trilateral could come at the expense of the highly prioritized bilateral defense relationship with Japan itself. The Philippine-Japanese bilateral relationship is deeply important to leaders in Manila who, while seeking a closer defense relationship with Washington, seek to simultaneously diversify their security partners. Indeed, one of the motivations for deepening the Philippine-Japanese defense relationship came after the 2012 Scarborough Shoal incident, which is still remembered in Manila as a moment of American unreliability. While the aftermath of the incident resulted in a deepening of bilateral security ties between the Philippines and United States, Manila also responded to its loss of the Scarborough Shoal through a project of expanded defense relations with Tokyo.

It is not clear that Philippine-Japanese bilateral security cooperation has actually slowed as a result of progress in the trilateral relationship. In February 2023, for example, Japan and the Philippines signed a defense agreement enabling future bilateral security cooperation including expanded bilateral exercises and greater access rights for Japan Self-Defense Forces soldiers in the Philippines. Nevertheless, the security relationship with Japan is appealing for Manila precisely because it provides the opportunity to work more closely with a strategically aligned U.S. ally without risking the backlash from Beijing that direct cooperation with Washington would provoke.

So, were this bilateral relationship to be even partially subsumed under an umbrella of a trilateral including the United States, the Philippines would lose one of the primary benefits of working with Japan in the first place. The delicate balance Manila has struck between cultivating its security ties with both Tokyo and Washington allows it to navigate the complex geopolitics of its region while minimizing risks. Given the often volatile nature of U.S.-Philippine security ties, linking them even partially to the much stabler relationship with Tokyo appears risky to Manila.

Getting It Right

In light of these considerations, what does an optimal balance in the U.S.-Japanese-Philippine trilateral relationship look like? First, leaders in all three countries should deemphasize overt transactionalism in the trilateral. This means avoiding the perception that Washington’s top priority is locking Manila into a series of agreements that could compromise its freedom of action. Washington is seeking greater basing and overflight rights, and it makes sense for the United States to secure some formal agreements when trilateral relations are at a high point. But there is a risk in overemphasizing the on-paper aspects of the partnership at the expense of building mutual trust. 

Second, Washington should join Manila in encouraging Tokyo to play a more prominent role in shaping the dynamics of the trilateral relationship. Japan enjoys a high level of trust in the Philippines — more than any other country, according to several polls. If there are concerns within the United States about certain Philippine defense capabilities or strategies, it seems preferable to cede some leadership to Tokyo rather than defaulting to a U.S.-dominated approach. Indeed, defense experts in Manila frequently stated that while their main desire was for the trilateral to become more Filipino, in the absence of that, a more Japanese-led relationship would also be welcomed.

Finally, all three parties would benefit from focusing future trilateral security cooperation away from a potential conflict over Taiwan as much as is feasible. This specific focus could obfuscate broader, and arguably more universally shared, strategic objectives, including deterrence in the South China Sea, improving the capabilities of the Philippine Armed Forces, and working toward greater trilateral military interoperability. Notably, the June 2023 trilateral Coast Guard exercise and its focus on protecting local fishing rights was widely praised by those I spoke to in Manila. Advancing shared objectives helps reinforce a shared trilateral alignment on regional security. As a result, by subtly shifting the focal point away from Taiwan, all three countries could, somewhat paradoxically, strengthen their deterrence posture vis-à-vis Taiwan.



Ryan Ashley is an intelligence officer in the U.S. Air Force with extensive operational experience in East Asia and Japan and a Ph.D. candidate at the University of Texas Lyndon B. Johnson School of Public Affairs. He is also a lecturer with the Air Force Special Operations School. He has previously published on East Asian security and international relations with War on the Rocks, Nikkei Asia, and The Diplomat. 

The views expressed here are those of the author and do not represent those of the U.S. Air Force, the Department of Defense, or any part of the U.S. government.

Image: U.S. Marine Corps photo by Cpl. Yvonne Iwae