F-15E Strike Eagles, assigned to the 494th Fighter Squadron from Royal Air Force Lakenheath, England, rest on the flightline at Los Llanos Air Base, Spain, Sept. 16, 2016. During Tactical Leadership Programme 16-3, U.S. service members trained side by side with NATO allies and partners, preparing them to meet future security challenges as a unified force. (U.S. Air Force photo/Staff Sgt. Emerson Nuñez)