Two U.S. Air Force F-16 Fighting Falcons from the 177th Fighter Wing of the New Jersey Air National Guard, left, and a Bulgarian air force MiG-29 Fulcrum fly the pattern in formation over Graf Ignatievo Air Base, Bulgaria, on July 13, 2015. The jets were part of Thracian Star, a bilateral training exercise to enhance interoperability with the Bulgarian air force and to bolster readiness to conduct combined air operations. (U.S. Air National Guard photo by Master Sgt. Andrew J. Moseley/Released)