The central purpose of American power is to provide security for the United States in a dangerous world. Before September 11, other states, especially other great powers, were perceived to be the main threat to the United States. To maximize its security, American policymakers worked assiduously to ensure that the United States held a favorable position in the global balance of power.
This template for thinking about American security policy has been altered somewhat by September 11. The United States still has to be deeply concerned with great power politics, particularly with the rise of China. But now it also has to confront Al–Qaeda, which has the United States in its gunsight and is determined to acquire weapons of mass destruction.
President Bush has not yet devised a clear strategy for combating terrorism. Nevertheless, he has been under intense pressure to view September 11 as a transformative moment that calls for the United States to become much more actively involved around the world. Indeed, some conservatives argue that it is time to create an American empire, where the United States dominates the entire globe and shapes it according to its own interests. Presumably, this ambitious strategy would keep great power rivals at bay as well as eliminate the terrorist threat.