The North Korean and Chinese Threats Are Growing. But so Is the Trilateral Response.

I recently spent a few weeks traveling between Seoul and Tokyo, participating in several conferences, including the Chosun Ilbo’s Asian Leadership Conference and the Nikkei Forum Future of Asia. My contributions in both Seoul and Tokyo focused on two key issues: the persistent negative news about North Korea and the increasingly positive developments in the United States-South Korea-Japan trilateral alliance. I address both issues in my recent Foreign Affairs article, “The Coming North Korean Crisis And How Washington Can Prevent It,” and in my new Washington Post article, “This nascent trilateral relationship is the best possible answer to China,” co-written with Max Boot.

On North Korea, much of the discussion at these forums revolved around the possibility of an October surprise by Kim Jong Un before the U.S. presidential election, North Korea's game plan, and Washington’s potential North Korea policy under a Trump administration (with most experts agreeing that a Biden second term would likely maintain the status quo). There were many questions about how our allies should respond.

Experts generally agree on North Korea’s strategy: perfecting its WMD capability with little intention of returning to denuclearization talks. Kim Jong Un has no incentive to negotiate with the United States, especially with his current level of support from China and Russia, allowing him to act with impunity. Even if Kim were inclined to make a deal under a Trump presidency, advancing North Korea’s nuclear program would be a logical step to increase his bargaining leverage, particularly after the humiliation at the Hanoi summit.

Additionally, discussions highlighted concerns over the burgeoning North Korea-Russia alignment, with North Korea shipping weapons to Moscow and the potential for Moscow to provide sensitive technology to North Korea in return. One expert noted that Washington will soon need to prioritize its focus—either on the unrealistic pursuit of denuclearization or on preventing the North Korea-Russia nexus from expanding and improving North Korea’s nuclear arsenal.

The main debate, however, was on what U.S. policy might look like if Trump returns to the White House and on how Washington and Seoul should respond to the North Korean threat. South Korean media extensively covered remarks by Elbridge Colby, a former Pentagon official in the Trump administration, who argued that U.S. extended nuclear deterrence against North Korea is losing credibility. He suggested that the U.S. military is no longer powerful enough to win multiple wars simultaneously and that addressing issues other than China risks U.S. defeat. His advice to South Korea was to be prepared to defend against North Korea alone or consider developing its own nuclear weapons, as the United States may not provide a viable defense umbrella. These comments, given South Korean perceptions of Colby’s potential role as national security advisor to President Trump, have understandably alarmed South Koreans.

While the potential of another Trump term is cause for concern in Asia (and elsewhere), the United States-South Korea-Japan trilateral relationship is a bright spot amid numerous global crises. The Biden, Yoon, and Kishida administrations agree on the urgency of deepening cooperation, particularly in economic security, intelligence sharing, and defense policy, to address the challenges from North Korea and China. One positive sign: Kishida’s first call to a foreign leader after returning from his summit with Biden was to Yoon. That would have never happened in the past, and it shows how the Japan-South Korea relationship is rapidly progressing.

A recent sign of China’s eagerness to regain diplomatic momentum was the China-South Korea-Japan summit in Seoul, the first such meeting since 2019. While no significant breakthroughs occurred, the leaders agreed to work together on supply chains, environmental, health issues, and restarting free trade talks. As noted in our Washington Post article, China’s desire to meet is seen as an attempt to interject itself into the close Japanese-South Korean alignment with Washington. Previously, such gatherings highlighted Sino-South Korean suspicion of Japan; now, they highlight Japanese-South Korean suspicion of China, which has become deeply unpopular in both countries.

The concern with the trilateral alignment is its sustainability amid potential leadership changes in the United States, South Korea, and Japan, where all three leaders face low approval ratings. Yoon, with three years left in office, remains committed to improving trilateral ties despite his ruling party losing to the opposition parties in the recent National Assembly election. Kishida is also likely to secure support within his party, whereas Biden faces immediate electoral danger. There is anxiety in both South Korea and Japan about a potential Trump return and its implications for the trilateral relationship. As a result, one emerging theme from these forums is the importance of reinforcing the South Korea-Japan leg of the trilateral relationship through a more formal strategic partnership or bilateral security agreement. This would enhance real-time intelligence sharing, joint military exercises, missile defense cooperation, defense industrial production, and command structure.

Additionally, fostering a friendly atmosphere between the younger generations of both nations is crucial. South Koreans love Japanese anime and food, while Japanese youth enjoy K-pop and K-drama. Building people-to-people ties and cultural exchanges can genuinely improve bilateral relations.

I left the region with some hope, seeing that both U.S. allies, South Korea and Japan, are committed to the trilateral relations and doing their part. At a dinner reception during the Nikkei Conference, Kishida emphasized Japan’s commitment to leading efforts in Asia to tackle global challenges, including AI, cybersecurity, demographic issues, and expanding ties with the Global South, Southeast Asia, and the Pacific Islands. His key message was that like-minded allies need to think outside the box. Yoon, who has vowed to turn South Korea into a Global Pivotal State (GPS), would very much agree. So would Biden, who has invested a lot of capital in nurturing the trilateral relationship. There is much cause for concern in East Asia but also some grounds for optimism about the ability of democracies to come together to address the threats they face.