That's the subhed on this new Pew Research Center poll. From the summary:
In the midst of two wars abroad and a sour economy at home, there has been a sharp rise in isolationist sentiment among the public. For the first time in more than 40 years of polling, a plurality (49%) says the United States should "mind its own business internationally" and let other countries get along the best they can on their own. […]
Four years ago, 42% agreed that the U.S. should "mind its own business" in international affairs; in December 2002, just 30% agreed with this statement.
At the same time, there has been a rise in unilateralist sentiment. Fully 44% say that because the United States "is the most powerful nation in the world, we should go our own way in international matters, not worrying about whether other countries agree with us or not." That is by far the highest percentage agreeing since the question was first asked by Gallup in 1964.
Link via George Stephanopoulus' Twitter feed.