Reaffirming alliance: The crucial importance of the US-Japan-South Korea trilateral summit

On Aug. 18, the leaders of the United States, Japan, and South Korea will gather for a trilateral summit at Camp David. The summit falls at an important time for the region, as critical alliances with Tokyo and Seoul grow more vital given the tensions surrounding perceptions in all three capitals as to China’s growing assertiveness and fears about North Korea’s expanding nuclear program. 

However, the summit’s true value lies in the three leaders meeting face-to-face for the second time in ten months, their previous meeting taking place at the East Asia summit in Phnom Penh in November 2022.

In an era marked by digital communication and virtual meetings, the upcoming trilateral summit’s emphasis on face-to-face diplomacy plays to President Biden’s deeply held belief that “in international relations, all politics is personal’, a proposition reaffirmed by the U.S. ambassador to Japan, Rahm Emanuel, in a pre-summit discussion at the Brookings Institution on Wednesday. As we have shown in our previous research, interpersonal face-to-face diplomacy provides unparalleled opportunities for intention understanding and trust building. By sitting across the same table, the leaders of the United States, Japan and South Korea are afforded an opportunity to engage in sincere dialogue, unravel misunderstanding, and develop relationships of trust with one another.

Trust is all the more important given the complexities of the region and the historical legacies of conflict, especially between Japan and South Korea. The geopolitical priorities and strategic interests of these nations diverge in significant ways, creating a web of concerns and potential sources of insecurity that must be carefully navigated. 

For South Korea, the existential threat posed by North Korea and the division of the Korean Peninsula remain paramount. Seoul’s reluctance to be drawn into a direct balancing strategy against China reflects this unique geopolitical reality. Meanwhile, Japan’s main security focus centers on China and its partnership with Russia, especially regarding the tense situation in Taiwan. Part of the delicate U.S. calculus is reassuring South Korea and Japan on these issues, while not creating insecurity in China.

Furthermore, both South Korea and Japan harbor concerns about the stability of their alliance with the U.S., especially in light of the upcoming 2024 American presidential election. North Korea’s growing nuclear capability and Russian President Vladimir Putin’s nuclear brinkmanship in relation to Ukraine has raised growing anxieties in both capitals about the credibility of the U.S. nuclear guarantee. With public opinion polls suggesting in the aftermath of Russia’s invasion of Ukraine that three quarters of the South Korean public support Seoul developing its own nuclear weapon, the Biden administration is urgently trying to reassure Seoul and Tokyo that the security of the United States is indivisible with that of its two key Asian allies.

The Biden administration also recognizes the risks of basing cooperation on particular leader-to-leader relationships that cannot be sustained indefinitely. To this end a key purpose of the summit on Friday is to create mechanisms and processes that institutionalize and embed trust. Here, officials are emphasizing the value of continued communication (hotlines), cooperation at broader societal levels (people-to-people exchanges), and other efforts to embed trust. South Korean President Yoon Suk Yeol has made significant progress in a very short period of time improving relations with Japan, including diplomatic engagement with Japan’s prime minister, Fumio Kishida, and a “groundbreaking” deal that helped to mend ties over damages sought for Korean forced-labor victims.

The upcoming trilateral summit is not merely a momentary reaffirmation of shared commitments; it is a critical starting point for continued cooperation and trust-building among the United States, Japan and South Korea. The summit serves as a beacon for a future where these nations continue to weave a fabric of trust, collaboration and shared values. The mechanisms and processes aimed at institutionalizing and embedding trust that will be put into place on Friday must be nurtured and sustained beyond the conference halls of Camp David. The future of the region, characterized by stability, prosperity and democratic resilience, hinges on this sustained engagement. Through dedicated commitment to these principles, the U.S.-Japan-South Korea alliance can transition from momentary consensus to enduring partnership, setting a remarkable precedent for diplomacy in the 21st century.

Marcus Holmes, Ph.D., is professor and department chair of Government at William & Mary, and is a faculty affiliate to William & Mary’s Global Research Institute. Nicholas J. Wheeler, FAcSS, FLSW, is professor of International Relations at the University of Birmingham.