Since the end of the Second World War, the role of the United States in the international arena has been closely linked to the stability of its security alliance system. For strategic reasons, one of the major goals for the U.S. foreign policy has always been preventing the rise of a hegemonic power in Eurasia. Actually, history and geopolitics tend to show that the global balance of power strictly depends on dynamics, threats and acting players in Eurasia. Despite Chinas growing global influence, it is in Asia-Pacific that the Chinese quest for power has played out more vividly. In this framework, the partnership between Russia and China represents a source of worries for the West as a whole and, more specifically, the gravest strategic threat to U.S. overseas interests.