Rearming the Law Popular Motivations for Amendment of Japan’s Pacifist Constitution

Article IX of the Japanese Constitution stipulates that the nation shall not fight wars or maintain military power. Despite Japan’s possession of significant “Self-Defense Forces,” opinion polls indicate that the Japanese public remained largely opposed to amendment of Article IX until September 2001. After that time, poll responses favoring amendment have been significantly higher (though not always above 50%), and this paper seeks to determine the cause of increased support for change. Three overarching theories are evaluated as possible explanations: realism (which views Japan’s security situation as the cause); domestic politics (which views political forces within Japan as the instigators of change); and normative theory (which attributes the shift to cultural changes that go deeper than either security or politics).

The main finding of this paper is that, while various changes in Japanese security, politics, and culture enabled a change, the political leadership of Prime Minister Koizumi Junichirô was the primary determinant of the timing of the opinion shift on Article IX. Factors that likely helped enable a change in public attitudes include: growing threats from China and North Korea; demise of Japan’s leftist political parties; marginalization of reform opponents in the governing party; the public’s gradual acceptance of increasingly assertive Japanese defense policy and of the Self-Defense Forces; and emergence of a norm of contributing to international peace. Factors that do not appear directly linked to the Article IX shift include: reduced trust in the United States for protection; vulnerability in Japan’s economic security; generational change; and rising nationalism. International terrorism does not seem to have contributed to the initial change in Article IX opinions but may have helped keep poll numbers high after the shift.

These findings tend to discredit realist and normative explanations and tend to support the domestic politics set of arguments. To the extent that these findings support speculation about Japan’s future, they suggest a continuation of gradual change in Japanese defense posture. They suggest that Japan may well amend Article IX but maintain its alliance with the United States, perhaps eventually making more substantive contributions of Japanese forces to joint operations with the United States and the United Nations.