America's Debt Is Greater than Entire Eurozone's (and U.K.'s) Combined Debt

The Republican side of the Senate Budget Committee will release this chart later today, clearly showing that America's debt is greater than the combined debt of the entire Eurozone and the U.K.:

As the chart shows, America's debt is currently $15.1 trillion, while the Eurozone (which includes France, Germany, Greece, Italy, Spain, the U.K., and others) has a combined debt of $12.7 trillion. (All dollar amounts are in U.S. dollars, and the data refers to closing 2011 numbers.)
The Eurozone is larger than the United States, so America's debt per capita also exceeds the Eurozone's. According to the Census Bureau, the U.S. has a population of 313 million, whereas the Eurozone has a population in excess of 331 million.
Republican presidential candidate Mitt Romney frequently warns that the United States should not become like Greece. "We need to rein in government and unleash the extraordinary vitality and creativity of the American people," Romney wrote in a December op-ed. "We must not wait to suffer a crisis like Greece's or Portugal's to right the ship of state."
But with charts like this, that formulation might already be out of date, considering the enormity of America's debt burden.