A crew chief from the 123rd Expeditionary Fighter Squadron, 142nd Fighter Wing, Oregon Air National Guard, performs pre-flight checks on an F-15C Eagle fighter aircraft during a theater security package deployment Sept. 25, 2015, at Campia Turzii, Romania. The U.S. Air Force’s forward presence in Europe allows cooperation among NATO allies and partners to develop and improve ready air forces capable of maintaining regional security. (U.S. Air Force photo by Staff Sgt. Christopher Ruano/Released)