October 22 is the third and final U.S. presidential debate in the close race between President Obama and Mitt Romney.

The theme of this debate is foreign policy, but viewers should still expect some budget, tax, and economic talk to creep into the discussion.

Among the topics to look for: the global fallout from the European debt crisis and the lessons the U.S. should take from it; U.S. taxation of multinational corporate profits versus other countries' lower corporate tax rates; and the budgetary impact of the conflicts in Iraq and Afghanistan.