Can ROK-US alliance and multilateral security framework co-exist?

By Lee Jong-eun

This year marks the 70th anniversary of the Korean Armistice Agreement and the subsequent signing of the ROK-U.S. Mutual Defense Treaty. For the past seventy years, the ROK-U.S. alliance has been a critical framework for South Korea's security. But why did South Korea actively pursue a bilateral security pact rather than a multilateral alliance similar to NATO? To answer this question, it is helpful to briefly review South Korea's geopolitical calculations during the Korean War.

The U.S. intervened in the Korean War, and led the multilateral U.N. Command. The post-armistice security reassurance U.S. policymakers offered initially to South Korea was also multilateral. The U.S. proposal was for the U.N. Command member states to collectively sign the Greater Sanction Statement, committing to re-intervention should the communist powers violate the armistice. However, then-South Korean President Syngman Rhee rejected the Greater Sanction Statement as an insufficient security reassurance. Distrustful of the multilateral security commitment from countries with little security interests in the Korean Peninsula, Rhee advocated a bilateral defense pact with the U.S. instead. To mitigate South Korea's opposition to the armistice, the Eisenhower administration eventually conceded to ratifying the mutual defense treaty.

Henceforth, South Korea has relied upon this "hub & spoke" security framework, relying almost exclusively on the superpower's security guarantee with limited security cooperation with other member states of the U.S.-led alliance. In general, South Korean policymakers did not perceive the necessity for multilateral security cooperation when they were reassured of security protection by the bilateral defense pact. Pursuing a trilateral alliance with neighboring Japan, in particular, risked political controversies over the unresolved historical legacy between the two U.S. allied states. Even if South Korea aspired to pursue a multilateral security framework, its capacity to contribute to such a framework was limited in the past.

Recently, however, South Korea's security strategy has been changing. The trilateral security consultation between the U.S. Japan and South Korea have increased under the current Yoon Suk Yeol government. Aside from meetings during multilateral summits, the three heads of state met separately last year in Phnom Penh and have announced another trilateral summit this summer in Washington to discuss multiple areas of security cooperation. The South Korean government has also expanded security cooperation with NATO as one of NATO's official Asia-Pacific Partner (AP4) states. At the 2023 NATO summit, President Yoon signed Individually Tailored Partnership Programs (ITPPs) for cooperation in areas such as cybersecurity and counterterrorism. The Yoon Government has also indicated that South Korea might participate in NATO's Battlefield Information Collection and Exploitation System (BICES) to increase military information sharing.

Why are such policy changes arising? There are criticisms that South Korea is needlessly risking security entanglement overseas and political controversies at home when South Korea already has security reassurance from the U.S.-ROK alliance. However, complementing the bilateral alliance through multilateral security cooperation with other U.S. allies is a strategy South Korea should consider to bolster its current security framework.

Despite seventy years of remarkable duration, the ROK-U.S. alliance has encountered tensions at multiple intervals, often over the credibility of the U.S. security commitment. Will the U.S. defend South Korea at the risk of security costs? Could the U.S. entrap South Korea in a costly geopolitical conflict? Such tensions have commonly evoked two policy responses in South Korean politics: to pursue "security independence" or to establish even closer alignment and trust with the U.S. Both approaches have merits, but there is a third approach that has been less discussed in South Korean politics. Why not collaborate with other U.S. allies who encounter similar dilemmas of balancing the risks of "abandonment and entrapment" in their alliance with the superpower?

South Korea's security dilemma, "Will Washington risk Seattle to defend Seoul?" is similar to Japan's dilemma, "Will Washington risk Tacoma to defend Tokyo?" South Korea's apprehension toward U.S-China geopolitical rivalry and the escalation of the Russia-Ukraine War are security concerns also shared by European states. Subsequently, South Korea's pursuit of partnership with other U.S. allies to enhance "collective bargaining" with the "hub" could help mitigate the security risks challenging the ROK-U.S. bilateral alliance.

What deters the U.S. from abandoning South Korea? The biggest deterrence is the mutual defense treaty. However, deterrence will be strengthened further if other U.S. allies advocate for South Korea's security. At NATO Summit, President Yoon declared, "Security in the Atlantic and the Pacific Ocean can never be separated," in an appeal for NATO's support for security deterrence against North Korea's provocations. In the past, South Korea had little strategic value to Europe. Today, by expanding arms export to Europe and committing to Ukraine's post-war reconstruction, the South Korean government has been demonstrating its strategic value to NATO member states.

Concerning Korea-Japan relations, I recall an observation made by one U.S. policy expert. "If Korea proposes a policy, the U.S. might listen. If Japan proposes a policy, the U.S. might listen. But when Korea and Japan propose a policy together, the U.S. will definitely listen." Even if the trilateral alliance is still premature, South Korea's security interest lies in ensuring that the ROK-U.S. and Japan-U.S. alliances do not undercut each other's effectiveness but rather perform complementary roles to ensure the "entire wheel" of the U.S. regional alliance rolls smoothly.

Seventy years ago, the ROK-U.S. alliance was likely the only realistic guarantee for South Korea's security. Today, the bilateral alliance is still the best security guarantee for South Korea. While celebrating the 70th anniversary of the alliance, South Korea should reinforce the "hub & spoke" security pact through collaboration with other "spokes" in the U.S. alliance. In the past, such a proposal might have been unrealistic for war-torn South Korea. Today's South Korea, however, has a greater capacity to combine the bilateral and multilateral components of its security framework to ensure that the ROK-U.S. alliance continues to "go together" favorably toward South Korea's security interest.

Lee Jong-eun, Ph.D., is assistant professor of political science at North Greenville University.