Abstract
China and Japan used to have good energy cooperation before China switched into a net oil importer in the mid-1990s, but the recent years have witnessed an increasingly intensive competition between the two countries over petroleum supplies. While many saw such competition as inevitable with China’s growing energy demands, the paper argues that the energy relationship between the two countries was never separated from political and strategic concerns, and heavily affected by the concern of ‘relative gains’, as suggested by the neorealists. Like the case prior to the mid-1990s when the non-energy factors underpinned the Sino–Japanese energy cooperation, the key factors that prevented the two from continuing energy cooperation today also lay in political and strategic aspects. Being two regional powers in East Asia, China, and Japan need to recognize the fact that their lack of energy cooperation due to mutual political distrust will not only impair their own energy security, but may also have negative implications on regional stability.