The trajectory of the United States in global climate governance over the past three decades presents a paradox. As the world’s largest historical emitter of greenhouse gases and a scientific and technological powerhouse, its leadership is indispensable for any effective global response. Yet, its policy path has been marked not by steadfast leadership, but by profound volatility, oscillating between engagement and retreat. This chapter examines the evolution of U.S. climate policy from the administration of George H.W. Bush to that of Joe Biden, arguing that its erratic nature is not a series of random fluctuations but a reflection of deep-seated structural tensions within the American political economy.