Mind the Gaps: Reading South Korea’s Emergent Proliferation Strategy

South Korea has long been on the list of potential over-the-horizon proliferation challenges, but growing debates in Seoul about its nuclear options are quickly moving it toward the front of the US nonproliferation agenda. Indeed, proliferation concerns featured prominently at the April 2023 Republic of Korea (ROK)-US summit, where Washington sought South Korean reaffirmation of its “longstanding commitment to its obligations under the Nuclear Nonproliferation Treaty” in return for efforts to bolster extended nuclear deterrence. For decades, calls in South Korea for nuclear armament remained relegated to the political fringes and did not receive serious policy attention. That has begun to change in recent years. South Korean nuclear weapons advocates and those sympathetic to the idea are becoming more numerous, louder, and are increasingly drawn from a broader cross-section of the national security community. In January 2023, South Korean President Yoon Suk-yeol publicly stated that if threats continue to worsen, South Korea might develop nuclear weapons. This is the first time a South Korean president has made such comments. Perhaps most importantly, there has been a subtle evolution of the public discourse, from basic arguments about why nuclear weapons may be desirable to