The decline or renewal of U.S.power has again been a hot discourse in the world stage since the global financial crisis. This article analyzes the political motivations that lead to opposing conclusions. Three themes-America’s economic recovery，smart power，and the rise of emerging powers-are new in this round of debate. America’s adjustments in its development and international strategies are a decisive factor in shaping its future destiny. While the emerging powers like China have resulted in the relative weakening of U.S. global influence，its power will continue to grow and its international primacy will be maintained for at least two to three decades to come.