American exceptionalism: a realist view Posted By Stephen M. Walt

Americans like to think the United States is different (i.e., "better") than other countries. The idea that the United States is "exceptional," a "shining city on a hill," or destined by Providence to play a special role in world history, is a popular theme among politicians and widely embraced by ordinary U.S. citizens. As Karen Tumulty pointed out in an interesting Washington Post piece last week, the idea of "American exceptionalism" has also become yet another stick that conservatives are using to beat up President Obama, because he supposedly doesn't think we're all that unique. (In fact, like most politicians, Obama has praised America's "exceptional" qualities throughout his career).
Every country has certain unique features and interests, of course, but the idea that any state is truly "exceptional" is sharply at odds with a realist view of international politics. Realism depicts international politics as an anarchic realm, where no agency or institution exists to protect states from each other. As a result,  states must ultimately rely on their own resources and strategies to survive. It is, in other words, a "self-help" world, and this situation forces all states -- and especially the major powers -- to compete with each other, sometimes ruthlessly. Although realists acknowledge that domestic politics sometimes matters and that there are important differences between different great powers (and different leaders), the most important difference between states is their relative power.More at:
http://walt.foreignpolicy.com/posts/2010/12/06/american_exceptionalism_a_realist_view