A B-52H Stratofortress from Barksdale Air Force Base,

A B-52H Stratofortress from Barksdale Air Force Base, La., is parked on the tarmac at Royal Air Force Fairford, United Kingdom, June 1, 2017. Aircraft from more than 10 countries participated in Arctic Challenge, a multinational training exercise aimed at maintaining relationships and trust essential for ensuring regional security. They practiced evaluating aircraft, personnel and weapons capabilities, as well as mobilizing and training in multinational operations. (U.S. Air Force photo/Senior Airman Curt Beach)