This chapter applies Hsu’s psycho-cultural framework to examine the affective and structural logics underlying the behaviors of China and the United States. Drawing on the concepts of active and passive superiority, individual-centered versus situation-centered orientations, and psychosocial homeostasis, the chapter explains the cultural origins of American expansionism and Chinese non-interventionism. It compares how each society fulfills social needs—through individual ambition and external conquest in the U.S., and kinship-based mutual dependence in China—and traces how these orientations shape their attitudes toward international relations. Through a comparative analysis of historical development, national character, and prejudice, the chapter highlights a centrifugal tendency in U.S. policy and a centripetal tendency in China’s. The chapter further explores how conformity-induced prejudice underpins American interventionism, while China’s appeasement strategy stems from cultural ideals of harmony and face. It concludes that Hsu’s theory provides a powerful explanatory lens for understanding the divergence in state behaviors between Western and Eastern civilizations.