As of August, China owned $1.185 trillion in U.S. Treasuries. That's about 30% of the chunk of U.S. public debt that's held by foreign countries. The rest of the $19.5 trillion debt is owned by either the American people or by the U.S. government itself. We need them to buy some of our government debt, since we're not going to cut spending. But they need us too, to buy their junk. Masses of their people live in poverty and their economy depends on selling exported goods. We're not their only market, of course.