Besides Afghanistan and Iraq, which world situation could push the United States to war?

Fortunately for us, the U.S. is a smart country that doesn't initiate war these days. Other than the problems in Afghanistan and Iraq, there aren't many things that could cause the U.S. to go to war at the moment. One though could be the oil disputes in the middle east, which could possibly go south if we are restricted from our power supply. Another possibility for war could be terrorist organizations, should they become too large, or frighteningly organized. The last would be a dispute with China, since we owe them so much debt, and we also want to liberate them from their communist rule.