This paper examines Japan-China relations in the late 1990s by examining their negotiations over East Asia's regional leadership. After the Cold War ended in the early 1990s, Japan relied on the U.S.-Japan alliance to structure East Asia's new international order; the alliance expected close cooperation with East Asian countries such as China to maintain the region's stability. Japan economically and environmentally supported China to reduce any disagreements over international security policy. However, during negotiations, China frequently cited history and the Taiwanese issue in an attempt to contain expansion of the Japan-U.S. military cooperation, resulting in increased Japan-China confrontation over security issues. China did, however, actively agree with Japan's cooperation proposal, regardless of its perpetual ill feelings toward Japan. Therefore, although Japan-China economic relations strengthened, their security relations remained conflicted. Such complex relations defined Japan-China relations after the cessation of the Cold War.