How much will the war on terrorism cost? If past experience is any indication, there are bound to be a few hidden expenses. As it takes on the axis of evil, the Pentagon is running up what it refers to as "incremental costs" -- expenses over and above the cost of training and deploying troops overseas. But when the General Accounting Office took a look at $2.2 billion the Defense Department spent enforcing no-fly zones in Iraq and keeping peace in the Balkans in 2000 and 2001, it found at least $101 million in what it calls "questionable expenditures." Here are a few of the iffier expenses racked up at air bases in Saudi Arabia and the United Arab Emirates.