The author argues that the extent of Japanese cooperation with the American-led war on drugs since 1989 has largely been determined by domestic factors. Internationally, Japan's entrance into the global partnership has reflected the growing linkage of U.S. pressure on the drug war with its pressure on bilateral economic relations. Yet since the mid-1950's, Japanese drug policy has been shaped by the nature of its own domestic threat as perceived by Japanese government and society, and the rivalry among agencies responsible for controlling illicit drugs. The article concludes that, while government questions and an expanded role in foreign economic policy lie at the core of the global partnership on drugs, these areas are also likely to engender conflict between the U.S. and Japan on this issue. 27 notes