Japan Tests the Nuclear Taboo

This article examines whether recent changes in the security environment, including North Korea’s nuclear test of October 2006, are driving Japan to consider the acquisition of its own nuclear deterrent. It argues that a combination of three factors have thus far sustained Japan’s nuclear restraint: (1) national identity as a non-nuclear weapon state, (2) commitment to global nuclear nonproliferation and disarmament, and (3) realist security calculations. Partial changes in these factors have provoked in Japan a new round of debate about the nuclear question that can be grouped around three general options: (1) move toward a nuclear weapons option, (2) robust conventional defense and a stronger alliance with the United States, and (3) a more assertive nonnuclear diplomacy. The article concludes that the most likely Japanese course for the time being is to strengthen the alliance with the United States and improve conventional defense capabilities, including missile defense. Although the taboo about public discussions of the nuclear weapons option may be weakening, Japan will continue to forgo that option.