A U.S. service member temporarily assigned to Osan Air Base, Republic of Korea, in support of exercise Key Resolve sleeps at the Osan Fitness and Sports Complex on March 2, 2015. The Key Resolve exercise is an annual training event designed to ensure readiness to defend the Republic of Korea and sustain the capabilities that strengthen the ROK-U.S. Alliance. (U.S. Air Force photo by Staff Sgt. William Banton/Released)