Japan's U.S.-imposed postwar constitution renounced the use of offensive military force, but, as Sheila Smith shows, a nuclear North Korea and an increasingly assertive China have the Japanese rethinking that commitment, and their reliance on United States security. Japan has one of Asia's most technologically advanced militaries and yet struggles to use its hard power as an instrument of national policy. The horrors of World War II continue to haunt policymakers in Tokyo, while China and South Korea remain wary of any military ambitions Japan may entertain. Yet a fundamental shift in East Asian geopolitics has forced Japan to rethink the commitment to pacifism it made during the U.S. occupation. It has increasingly flexed its muscles-deploying troops under UN auspices, participating in coercive sanctions, augmenting surveillance capabilities, and raising defense budgets. Article Nine of Japan's constitution, drafted by U.S. authorities in 1946, claims that the Japanese people