Japan’s Cold War nuclear decisionmaking: Improving upon competing theoretical perspectives

Abstract

This paper investigates Japan’s self-contradictory nuclear status, which has constituted a puzzle for international relations theorists and historians who have advanced several competing interpretations for this peculiar development. Adherents of the security model assert that Japan’s general weakness vis-avis others in the region, or the availability of a credible security guarantor through its alliance with the United States, explains Tokyo’s decision to forgo a homegrown nuclear deterrent. Recently, however, opponents of this view have instead favoured an ideational approach which focuses on the threat and identity perceptions of Japanese leaders. This article presents these two competing interpretations of the proliferation puzzle and applies them to Japan’s postwar nuclear decision-making. The paper demonstrates the limits of the security model and then improves upon the ideational approach by incorporating the oft-overlooked two-level game assumption popular with foreign policy analysis scholars. In doing so, I recognise the importance of focusing on Japanese leaders rather than international systemic factors, but also acknowledge that these individuals play a two-level game. They must, in turn, not only contend with the public’s antinuclear attitudes but also their nation’s alliance with the United States—the cornerstone of postwar Japanese security policy.