This article explores the two major theories of International Relations, Realism and Idealism, and their relevance to the complex relationship between China and the United States. It discusses the history of the China-US relationship and how it has shifted between Realism and Idealism over time, with the current US administration taking a more Realist approach. The article also highlights the importance of economic power in today's world and the role of international laws and organizations in fostering cooperation and trust amongst nations.