After the US-South Korea Summit: Seoul’s Diplomatic Achievements and Challenges

South Korean President Yoon Suk-yeol traveled to the United States in April on a state visit. The stakes were high for Yoon’s government. It needed to show diplomatic success in its interactions with the Biden administration. Domestically, President Yoon faces low job approval ratings and controversies over his policies, including the decision to mend strained diplomatic ties with Japan. Internationally, Yoon’s government faces challenges in responding to North Korean nuclear threats, the Russia-Ukraine War, the hostility between China and Taiwan, and U.S.-China economic tensions. 

During the state visit, Yoon attended a marathon of publicized events. He visited the Pentagon’s National Military Commerce Center and NASA’s Goddard Space Center. He addressed a joint session of the U.S. Congress, and held his summit with U.S. President Joe Biden. Much of the media coverage was on Yoon’s lavish welcome from the U.S. government and Yoon’s singing of American Pie at the White House State Dinner. But underneath the celebratory affirmations of the 70-year-old alliance between South Korea and the United States, what were the South Korean government’s tangible diplomatic achievements? 

The Usefulness of a Declaration

Coming into the summit, the South Korean government pursued diplomatic achievements in three policy areas: strengthening U.S. reassurance on nuclear deterrence, expanding bilateral cooperation in the economic and security realms, and maintaining South Korea’s strategic maneuverability in geopolitical conflicts. In each area, Yoon’s government achieved successes and ran into limitations.  

First, the summit announced the Washington Declaration, which reaffirmed the U.S. commitment to extended nuclear deterrence by establishing the bilateral Nuclear Consultation Group (NCG). In return for South Korea’s pledge not to pursue independent nuclear armament, the U.S. reaffirmed bilateral consultation, with the planning and deployment of deterrence measures against North Korea’s growing nuclear threat. 

Additionally, the U.S. pledged to deploy naval and aerial strategic assets to counter North Korea’s provocations, including regular visits by U.S. nuclear submarines to South Korean ports. To South Korean domestic politicians increasingly skeptical of the reliability of extended nuclear deterrence, the Washington Declaration signals further institutionalization of the U.S. security commitment to the bilateral alliance. While critics have noted that the NCG’s scope will likely be more limited than that of NATO’s Nuclear Planning Group, the NCG’s bilateral character promises to give South Korea a greater voice in nuclear deterrence coordination than any individual NATO member state has.         

The Washington Declaration’s limitations lie in its sustainability. How often will NCG meetings be held, and at which levels of government? How regularly will the U.S. deploy strategic assets, including nuclear submarines, to South Korea? The Declaration does not commit permanent deployment of U.S. strategic and nuclear assets in Korea. Future U.S. administrations could reduce the NCG’s activities as U.S. strategic priorities shift. South Korea’s anxiety remains — if the institutional framework of the Washington Declaration is not codified into a binding and proactive long-term commitment, the latest signaling of U.S. security reassurances will lose its impact.          

Differing Goals Equal Limited Consensus

Second, the joint statement of the U.S.-ROK summit agreed to the expansion of bilateral cooperation in the economic, technological, and cybersecurity realms. The joint statement announced the establishment of a Next Generation Critical and Emerging Technologies Dialogue led by the two countries’ national security advisors. The goal is to enhance cooperation in tech sectors, encompassing semiconductors, biomanufacturing, and artificial intelligence. 

The joint statement also announced the establishment of a Cybersecurity Cooperation Framework to combat cybercrimes and secure cryptocurrency and blockchain applications. Establishing these additional institutional linkages will provide opportunities for South Korean officials to directly engage their US counterparts on multifaceted dimensions of economic and technological cooperation.         

The South Korean government, however, was unsuccessful in achieving consensus with the U.S. on several economic policies. Though the joint statement affirmed closer consultation to ensure the U.S. Inflation Reduction Act and CHIPs Act do not adversely impact South Korean businesses, no concrete legal provisions were agreed upon at the summit. The meeting also did not resolve the South Korean domestic nuclear industry’s legal disputes with U.S. competitors over international exports. The Biden administration’s difficulty in reassuring protection of Korean economic interests in the U.S. market shows that institutional policy consultations do not always lead to policy agreements. When two allied governments face competing domestic political constraints, the zone of possible agreement can be very narrow.

Room to Maneuver for South Korea

Third, the South Korean government retained strategic maneuverability in its involvement in the Russia-Ukraine War. Before the summit, there was speculation about how Yoon’s government would respond to U.S. requests to send military aid to Ukraine. In the joint statement, South Korea pledged to support Ukraine through “political, security, humanitarian, and economic assistance.” There was no explicit mention of providing military assistance. Later, during an address at Harvard, Yoon reiterated that South Korea would closely monitor the situation in Ukraine and consider various options. He avoided explicit commitment to military assistance. Despite strategically aligning closer with the U.S. on geopolitical conflicts, the South Korean government kept its space for maneuver between providing strategic support for the West and mitigating direct conflict with Russia.      

Yet the South Korean government might have only pushed back a difficult strategic decision. If the war in Ukraine goes on, the U.S. will likely renew its request for South Korea’s help in replenishing Ukraine’s military arsenal. South Korea’s strategic deliberation might not be enough to avoid an eventual escalation of its confrontation with Russia. China has also criticized the U.S.-ROK summit’s pledge to preserve peace and stability in the Taiwan Strait as interference against China’s sovereignty. Despite South Korea’s security interest in avoiding direct conflict with China and Russia, Beijing’s hostility to South Korea’s strategic alignment with the U.S. could limit Seoul’s strategic maneuverability.    

To summarize, Yoon’s government achieved diplomatic success in several policy areas during the ROK-U.S. summit. These successes, however, reveal continuing diplomatic challenges and tasks for the South Korean government. Using the language of strategic bargaining, the South Korean government persuaded the U.S. to communicate more visible, flashier signals of commitment to extended nuclear deterrence. South Korea, however, is responsible for sustaining the long-term impact of these signals. South Korea succeeded in establishing additional institutional linkages with the U.S. to expand areas of policy cooperation. Seoul, however, knows that policy consultations might not always lead to consensus on areas of incompatible interests. Finally, South Korea has retained strategic maneuverability in its involvement in the Russia-Ukraine War. It will however face elevated challenges in maintaining this maneuverability if geopolitical tensions in Ukraine and Taiwan escalate. 

How the South Korean government addresses these challenges will determine whether the progress from this year’s U.S.-South Korea summit is real, mostly optics, or a stepping stone toward South Korea’s advancement of its geopolitical security interests.     

Jong Eun Lee has a Ph.D. in International Relations and is also an adjunct faculty at the American University School of International Service. Prior to this, he has served as a South Korean Airforce intelligence officer. His research specialty includes U.S. foreign policy, South Korean politics and foreign policy, alliance management, East Asian regional security. He has published articles in The Diplomat, National Interest, Responsible Statecraft, East Asia Forum, Eurasia Review, and The Korea Times.