As of  May 2011, the United States owed $14.3 trillion in debt to other countries. Heather Billings and Todd Lindeman of The Washington Post break foreign debt down by continent and then by country.

Foreign investors hold the largest share of the national debt. Estimated foreign holdings of U.S. Treasury securities have more than quadrupled since 2001. Some experts worry about the geopolitical consequences of foreign governments investing so deeply in U.S. Treasurys. But the investments also tie the fortunes of foreign governments more closely to those of the United States.

Via The Washington Post