This article evaluates China’s influence on the making and unmaking of economic détente in the 1970s. Utilizing recently declassified documents in Japan, the United States, and China, this article demonstrates that Chinese officials used both diplomatic and commercial means to influence their Japanese and American counterparts to prevent them from developing economic relations with the Soviet Union. During this process, Japanese and American industrialists had to carefully weigh up their participation in governments’ geopolitical schemes when pursuing business opportunities in the two socialist countries. This cautious attitude led to shifting dynamics in economic détente and varying outcomes for development projects. Chinese activism also prompted changes in Japan and the United States when decision-makers sought to benefit from the Sino-Soviet confrontation and maximize their economic and geopolitical gains. This article, therefore, features economic détente as a dynamic, multilateral process and emphasizes that the volatile geopolitics in Northeast Asia played a crucial role in ending détente and redrew the global Cold War to carry stronger economic overtones.