Two U.S. Air Force A-10 Thunderbolt II aircraft assigned to the 25th Fighter Squadron taxi on the flight line at Udon Thani Royal Thai Air Force Base, Thailand, March 15, 2013, during Cope Tiger 13. Cope Tiger is an annual multilateral aerial exercise designed to improve readiness and cooperation between U.S., Thai and Singaporean forces. (U.S. Air Force photo by 2nd Lt. Jake Bailey/Released)