A B-52H Stratofortress from Barksdale Air Force Base, La., lands at Royal Air Force Fairford, United Kingdom, June 1, 2017. The B-52 returned from a mission in support of exercise Arctic Challenge, a two-week multinational training exercise that included live-flying events to train on offensive and defensive air combat operations. Training with allies and joint partners improves coordination between allies and enables the U.S. Air Force to build enduring relationships necessary to confront a broad range of global challenges. (U.S. Air Force photo/Senior Airman Curt Beach)