How to Prepare for the Future After Seven Decades of the U.S.-South Korea Alliance

The United States is rolling out the red carpet on April 26 and 27 for South Korea’s pro-American President Yoon Suk-yeol, the Joe Biden administration’s second state visitor and the first South Korean president to address a joint meeting of Congress in a decade. Their commemoration of the seventieth anniversary of the U.S.-South Korea alliance is meant to showcase its resiliency, but sustaining it will require new efforts to deepen trust.

Yoon has taken a series of significant steps to demonstrate his fidelity to Washington, including aligning with the United States on policy toward China by moving high-tech supply chains and production to the United States. In addition, Yoon has pursued improved relations with Tokyo, a move welcomed by Washington as it tries to shore up trilateral U.S.-Japan-South Korea cooperation. But despite high levels of South Korean support for the alliance with the United States, Yoon’s public approval ratings [article in Korean] have stagnated in the low 30 percent range.

Trust and Deterrence

At the same time, questions about U.S. trustworthiness have been highlighted in Korean media in recent weeks by revelations that the United States monitored telephone deliberations between senior officials in the Yoon administration about U.S. requests that South Korea provide ammunitions to Ukraine despite domestic laws prohibiting directly supplying munitions for an active war effort. The content of the private communications was less damaging than the revelation that the United States was spying on a close ally.

The surveillance incident points to much deeper questions about U.S. reliability that Koreans are debating on both the security and economic dimensions of the alliance. The credibility of Biden’s personal assurances to Yoon at the upcoming summit will be critical to sustaining Korean confidence in the durability and depth of alliance coordination. However, the South Korean public is likely to look past the pomp and circumstance surrounding the visit to assess the United States’ credibility and commitment to South Korea.

On the security front, South Koreans increasingly see no viable pathway to North Korea’s denuclearization and have taken note of threats by an aggressive North Korean leadership to use nuclear weapons against the South. These threats have fueled a public debate over whether South Korea should negate North Korea’s advantage by attaining its own nuclear weapons, or whether South Korea can rely on U.S. pledges to defend it from attack. While the U.S. and South Korean governments are deepening nuclear planning coordination, including through exercises to forge responses to various nuclear use scenarios, the sustainability of the alliance will depend in part on how South Koreans assess the U.S. president’s political will to defend South Korea from a North Korean nuclear attack.

Partners and Competitors?

On the economic side, South Korean conglomerates have made major investments in the U.S. semiconductor and electric vehicle sectors, part of an effort to deepen economic integration and reduce the vulnerability of U.S. and South Korean supply chains to economic retaliation from China. But South Korean firms are also contending with provisions of the Inflation Reduction Act and the CHIPS and Science Act, both of which the United States passed in 2022, that are perceived as disadvantageous for Korean firms, even though separate, multibillion-dollar investment commitments will allow the firms to build new factories in the United States.

Some South Korean firms, such as Samsung and SK Hynix, are also contending with new restrictions on exports to China that put at risk their ability to profit from legacy factory production based there. The Biden administration will need to find ways to reassure South Korean investors that they will face a level playing field and have opportunities to earn returns on U.S. investments.

Forging Democratic Bonds

During his visit to Washington, Yoon will have extensive opportunities to explain to Americans the value and importance of U.S. cooperation with South Korea. Yoon’s address to a joint meeting of Congress will provide him with an opportunity to explain to lawmakers and the American people his own commitment to freedom, his dedication to upholding democratic values, and what South Korea’s aspirations to become a “global pivotal state” mean for its alliance with the United States.

During the summit, Presidents Biden and Yoon are expected to pledge to deepen extended deterrence in response to North Korea’s growing nuclear threat; enhance coordinated actions on intelligence sharing, cybersecurity, and space cooperation; and possibly expand joint efforts to promote clean power production through electric battery manufacturing, nuclear energy cooperation, and research on hydrogen fuel cells.

Past anniversaries have highlighted an alliance “forged in blood” that resulted from the U.S. decision to defend South Korea from communist aggression. While the threat from North Korea remains and concerns about China’s future have deepened U.S.-South Korea cohesion, the sustainability of the alliance will depend both on shared democratic values and on convergent economic interests that enable deeper integration of supply chains and technology.