Lt. Gen. Walter E. Buchanan III , the commander of American air forces in the Middle East , said in an interview at his headquarters here that there were really only two enduring bases for the United States in the region : Al Udeid in Qatar and Al Dhafra air base in the United Arab Emirates , from which the Air Force flies U-2 spy planes , the remotely piloted Global Hawk surveillance aircraft , and KC-135 refueling planes .