The United States has spent nearly $600 billion over the past 10 years putting combat forces into Afghanistan. Now it's going to cost an additional $5.7 billion over the next year or two just to transfer or return most of the troops and equipment we shipped into that country, according to a new report by the Government Accountability Office.

The size of the withdrawal is mind-boggling. But with the "fiscal cliff" approaching fast, it's worth taking a moment to realize that the costly Afghan operation is going on a credit card, along with the $1 trillion or more spent in Iraq.

Iraq and Afghanistan are the first U.S. wars in which the American public was not asked to pay a cent in additional taxes.