Despite earlier premonitions that East Asia might be 'ripe for rivalry', interstate relations in this region have generally become less tense in recent years. Naturally, this observation does not deny the existence of ongoing tension, such as pertaining to maritime disputes in the East and South China Seas. However, compared to those bygone years when East Asian states were fighting major wars and lined up in opposing camps, today's regional interactions are much calmer and multifaceted. This essay assesses these changing relations in the context of the literature on enduring rivalries and evolving Sino-American relations. It argues East Asian enduring rivalries, whether sustained, escalated or terminated, are nested in a larger contest for influence involving major powers. Washington's involvement plays a pivotal role affecting the trajectory and prospects for enduring rivalries in East Asia.