Stephen M. Walt in Foreign Policy:
In particular, the bedrock foundation of Obama's foreign policy is his recognition that the United States is very, very secure. That statement doesn't mean we have no interests elsewhere, but none of them are truly imminent or vital and thus they don't require overzealous, precipitous, or heroic responses. There's no peer competitor out there (yet) and apart from the very small risk of nuclear terrorism, there's hardly anything that could happen anywhere in the world that would put U.S. territory or U.S. citizens at serious risk. We will inevitably face occasional tragedies like the recent Boston bombing, but the actual risk that such dangers pose is far less than many other problems (traffic fatalities, industrial accidents, hurricanes, etc.), no matter how much they get hyped by the terror industry and our over-caffeinated media.
Instead, the greatest risk we face as a nation are self-inflicted wounds like the Iraq and Afghan wars or the long-term decline arising from a failue to invest wisely here at home. Recognizing these realities, Obama has reacted slowly and in a measured way to most international events.
More here.