Focusing on the role of harmony in Chinese international relations (IR) theory, this book seeks to illuminate Chinese understandings of world politics and foreign policy. Taking a decolonial approach and rooted in China's cultural and epistemic terms, the title first describes three traditions of the concept of harmony in ancient Chinese thought and then analyses three strands of contemporary Chinese IR theory that draw upon this traditional thinking. Despite their similarities in advocating a radical deepening of China's relations with other countries and intense interdependence as essential for global peace and prosperity, these Chinese IR theories understand the concept of harmony in different ways and present different recommendations for achieving harmonious relations. Based on this framework of harmonious IR, Chinese social scientists also argue for new directions in Chinese foreign policy in a manner that is complementary with China's policymaking system. In the case-study section, the authors apply harmonious IR perspectives to the Belt and Road Initiative and demonstrate how a better understanding of Chinese IR theories can shed light on motivations behind Chinese foreign policy. This work will be a valuable reference for scholars, students, policymakers, and general readers interested in Chinese politics, Chinese foreign policy, Chinese IR theory, and ancient Chinese philosophy.