The August 18 U.S.-Japan-South Korea summit held at Camp David seeks to institutionalize the rapid progress in Japan-South Korea security cooperation that was enabled by South Korean President Yoon Suk Yeol’s bold decision to resolve the World War II-era forced labor issue between Tokyo and Seoul.
In March 2023, Yoon decided to compensate Korean victims of Japanese forced labor by using South Korean funds. Five years ago, the South Korean Supreme Court ruled that Japanese companies should compensate these victims. The Japanese government, however, opposed this court ruling by insisting that this issue had already been resolved during the 1965 Japan-South Korea normalization process.
Alarmed by North Korea’s missile and nuclear weapons programs and wary of Chinese economic coercion and military assertiveness, President Yoon calculated that an improvement in relations with Japan was necessary to promote South Korea’s security interests.
But Yoon’s concession to Japan has not been popular. About 60 percent of the South Korean public oppose his decision. Although Prime Minister Fumio Kishida reciprocated by announcing Japanese funding for bilateral youth exchanges, this gesture is unlikely to satisfy many South Koreans who continue to feel that Japan has not adequately addressed the wrongs it inflicted during its colonial rule over Korea.
To make his political gamble pay off, Yoon has moved quickly to improve security cooperation with Japan as well as the United States. He hopes to lock in this progress so that it will be irreversible by the time his presidential term ends in 2027. The United States has long sought stronger Japan-South Korean security ties, and President Biden has seized this opportunity by hosting President Yoon and Prime Minister Kishida at Camp David for a historic trilateral summit.
The meeting’s anticipated results include regularized trilateral summits and 2+2 meetings involving foreign and defense ministers, the establishment of a trilateral hotline, and new agreements to improve collective military cooperation with a focus on missile defense, notably the development of a trilateral real-time missile intelligence-sharing system and the regularization of joint missile interception drills.
These outcomes will enhance deterrence and improve trilateral cooperation to deal with regional crises. Specifically, the new missile defense cooperation initiatives could address existing South Korean and Japanese deficiencies in some meaningful ways, notably by improving the accuracy of their missile data assessments and their ability to intercept various kinds of advanced North Korean missiles in a crisis situation.
However, the reinforcement of trilateral military ties will also entail risks and shortcomings posed by further intensification of the regional security dilemma. Strengthening trilateral security cooperation is likely to reinforce the confrontational divide between the United States, South Korea, and Japan on the one hand and China, North Korea, and Russia on the other.
As trilateral security cooperation grows, especially in the missile defense realm and potentially other military-strategic dimensions, it can exacerbate security concerns of North Korea and China, creating more reasons for them to harden their own security postures and promote their own trilateral military partnership with Russia. Pyongyang, Beijing, and Moscow can eventually begin to conduct joint exercises on a regular basis and deepen their overall military engagement and coordination.
The ties between Pyongyang, Beijing, and Moscow have long been fragile, but as the three become more concerned about their security environment, the attraction of greater strategic alignment may increase. The likelihood of such a scenario only seems to be growing in light of North Korea’s diminishing hopes for peace negotiations with the United States, China’s soaring hostility toward U.S. containment, and the West’s isolation of Russia following Moscow’s invasion of Ukraine.
Ultimately, in pursuing trilateral cooperation, Washington, Tokyo, and Seoul should seek to mitigate the destabilizing security dilemma dynamic. Simply expanding military cooperation can only make the regional security situation worse, not better. Improving security will require military deterrence to be coupled with robust collective diplomacy to manage and reduce tensions and minimize the risk of crisis and conflict with North Korea and China.
The Camp David summit will likely focus predominantly on trilateral security cooperation and leave much to be desired on the regional diplomacy front. Collective diplomacy should be an important pillar of the trilateral partnership, as well as collective defense.
Compared to the United States, which is now often constrained by American domestic politics from pursuing a moderate approach toward China or North Korea, South Korea and Japan – particularly South Korea – are freer from such domestic constraints and thus enjoy more policy flexibility. Washington should take advantage of its partners’ greater political flexibility to fashion a more coherent diplomatic strategy toward Beijing and Pyongyang.
Despite the Yoon administration’s hardline stance on North Korea, Seoul’s eventual policy objective is to resume diplomacy with Pyongyang and engage in nuclear negotiations based on a step-by-step framework, as underscored in its "audacious initiative" strategy. The Kishida administration also has a strong interest in re-engaging Pyongyang, not only for nuclear disarmament but also for resolving the Japan-North Korea abduction issue. In short, Seoul and Tokyo share an interest in spearheading a diplomatic initiative toward Pyongyang and should cooperate in doing so.
As part of a diplomatic deal to freeze and reduce North Korea’s missile and nuclear programs step-by-step, Japan and South Korea should be willing to relax sanctions, and Japan should address the issue of compensating North Korea for its colonial rule. Offering concessions to North Korea can be politically costly, but it eventually needs to happen in order to restart nuclear negotiations. Washington would incur less domestic political heat if Seoul and Tokyo are seen to lead the re-engagement effort.
While the United States may be increasingly tempted to pull Japan and South Korea closer to its side against China, it risks deepening tension and division within the trilateral partnership and should thus be avoided. Trying to transform the trilateral partnership into an overtly anti-China coalition does not serve Washington’s interest in developing a healthy, mutually beneficial trilateral partnership with Tokyo and Seoul.
Many in South Korea and Japan do not favor a stridently confrontational approach toward China given their countries’ vital security and economic interests. The costs of any military conflict with China that would be incurred by South Korea and Japan would be unbearable given their geographical proximity.
Tokyo and Seoul are also deeply concerned about how extensive U.S. high-tech trade controls against China will be. While both find a need to “de-risk” and diversify supply chains, they still see the importance of stable economic relations with China, which is their leading trading partner. These South Korean and Japanese concerns should be incorporated into the trilateral cooperation agenda.
In fact, when South Korea and Japan have better relations with China, it can make their engagement with the United States easier. Washington could draw a lesson from Nancy Pelosi’s trip to Taiwan — President Yoon refused to meet her when she stopped over in Seoul on her way home. If Seoul was more confident in its relationship with Beijing, the result might have been different.
In this context, the United States should encourage South Korea and Japan to develop a more credible reassurance policy toward China on the Taiwan issue in order to stabilize their relationships with China. The worse their relations with China, the more burdensome South Korea and Japan would feel about engaging more deeply with the United States.
Like the U.S.-China spy balloon saga earlier this year, there will likely be many more occasions when Washington faces enormous political pressure at home to act tougher on China than it intends or desires. As the South Korea-U.S.-Japan trilateral partnership expands and tension with China grows, Tokyo and Seoul’s relative political flexibility can prove valuable for reassuring Beijing.
Keeping expectations reasonable and well-balanced regarding China will be important for building a healthy and mutually beneficial trilateral partnership, but just as critical will be managing the internal political division between South Korea and Japan. The fragility of Japan-South Korea ties caused by thorny historical and territorial disputes will remain an obstacle to building resilience in the trilateral partnership.
In order to enable President Yoon’s bold decision regarding the forced labor issue, Japan must do more to promote reconciliation regarding its colonial rule over Korea. Tokyo should move beyond a strict transactional approach and promote greater Japanese awareness and empathy at the societal level regarding the suffering that Koreans endured during the colonial period.
South Korea-Japan government-to-government rapprochement that lacks the support of the broader South Korean polity and civil society is unlikely to endure and can eventually constrain the trilateral partnership.
