The Evolution of U.S. Extended Deterrence and South Korea’s Nuclear Ambitions

Extended deterrence has been a main pillar of the security alliance between the United States and South Korea (Republic of Korea [ROK]) since the end of the Korean War. The changing dynamics of US extended deterrence in Korea, however, affected Seoul’s strategic choices within its bilateral alliance relationship with Washington. Examining the evolution of US extended deterrence in the Korean Peninsula until the Nixon administration, this article explains why South Korea began its nuclear weapons programme in a historical context of the US–ROK alliance relationship. This article argues that President Park Chung-hee’s increasing uncertainty about the US security commitment to South Korea in the 1960s led to his decision to develop nuclear weapons in the early 1970s despite the fact that US tactical nuclear weapons were still stationed in South Korea.