U.S. Air Force Staff Sgt. Christopher Foster, a medical service craftsman with the 81st Medical Group, provides security for a C-17 Globemaster III aircraft during Joint Readiness Training Center (JRTC) 14-05 training at Fort Polk, La., March 14, 2014. The JRTC provides U.S. military units and personnel with realistic pre-deployment training scenarios in all aspects of armed conflict.