Movements toward the improvement of Sino–Soviet and Soviet–American relations from the mid-1980s gradually created a more favorable environment for a peace settlement in Cambodia. The United States showed some willingness to consider increased contact with the Vietnamese, while ASEAN countries and Vietnam demonstrated more willingness to solve the Cambodian problem. In this changing environment, Japan reassessed its Southeast Asia policy and intensified its diplomatic activities while continuing to link the settlement of the Cambodian conflict to the elimination of the Soviet foothold in Vietnam. The Japanese foreign ministers made proposals at regional meetings to solve the Indochinese problem, while Prime Minister Takeshita’s Peace Cooperation Initiative of 1987 was an unprecedented show of Japanese determination to make a larger contribution to the settlement of regional conflicts. Japan’s participation in a future Cambodian peace process was an important factor behind the formulation of such an initiative by Prime Minister Takeshita. Indeed, by maintaining active diplomatic channels with the main parties involved in the conflict and by continuing efforts to facilitate negotiations among them, Japan prepared the ground for its participation in the peace process that was about to materialize.