Leon Sigal of the Social Sciences Research Council examines the utility of a Japan-South Korea nuclear weapon free zone under three North Korea nuclear scenarios: containment, rapprochement, and collapse.

Focusing on failing containment, Sigal argues that if North Korea is unwilling to live up to its commitment to denuclearise, “a Japan-South Korea NWFZ might help to head off further proliferation in the region.” However, “a NWFZ intrinsically raises the question of Japanese and South Korean reliance on U.S. extended deterrence for their security and would constitute another decision point for reviewing their own non-nuclear status. The outcome thus depends critically on Japanese and South Korean views of North Korea’s nuclear arming and China’s rise. It might be best to begin negotiations sooner rather than later.” Initiating a Japan-South Korea NWFZ now might usefully prefigure a United States negative security guarantee to North Korea in a future rapprochement. In the event of a sudden collapse of North Korea, the existence of a NWFZ may avoid a regional “scramble to search for and seize its weapons, nuclear material, and nuclear facilities.”