The historical growth in the number and variety of Japanese nuclear veto players has made the country an extreme case of stasis in fundamental nuclear policies. Japan is not the only country to experience this phenomenon, however. In many advanced industrialized democracies, the old Manhattan Project model of top-down, centralized, and secretive nuclear institutions has gradually given way to more complex arrangements. And as a general rule, the more numerous the veto players, the harder the struggle to achieve major nuclear policy change.
"Veto Players, Nuclear Energy, and Nonproliferation: Domestic Institutional Barriers to a Japanese Bomb"
Journal Article, International Security, issue 2, volume 36
Although Japanese politicians have expressed interest in the bomb in the past, the country’s veto players make acquisition unlikely. Early research viewed proliferation exclusively as a response to security needs. Since the 1980s, most models have included domestic factors, but they have focused exclusively on a single actor whose influence can be negated if veto power is widely enough dispersed. Thus, despite Japan’s intimidating plutonium supply, and its persistence in building a complete fuel cycle, the country’s large and growing number of veto players suggests the continuation of a rigid nuclear weapons policy. As this analysis indicates, historical institutional analysis is crucial to understanding a state’s propensity for proliferation and should be considered alongside other contributing factors.