There Is Something Exceptional About American Exceptionalism.
Whenever American leaders refer to the "unique" responsibilities of the United States, they are saying that it is different from other powers and that these differences require them to take on special burdens.
Yet there is nothing unusual about such lofty declarations; indeed, those who make them are treading a well-worn path. Most great powers have considered themselves superior to their rivals and have believed that they were advancing some greater good when they imposed their preferences on others. The British thought they were bearing the "white man's burden," while French colonialists invoked la mission civilisatrice to justify their empire. Portugal, whose imperial activities were hardly distinguished, believed it was promoting a certain missão civilizadora. Even many of the officials of the former Soviet Union genuinely believed they were leading the world toward a socialist utopia despite the many cruelties that communist rule inflicted. Of course, the United States has by far the better claim to virtue than Stalin or his successors, but Obama was right to remind us that all countries prize their own particular qualities.
So when Americans proclaim they are exceptional and indispensable, they are simply the latest nation to sing a familiar old song. Among great powers, thinking you're special is the norm, not the exception.