A blast of fire shoots out of the barrel of an M1064A3 Mortar Carrier as soldiers of Apache Troop 5th Squadron, 7th Cavalry Regiment, stationed at Fort Stewart, Ga., continue their field training exercise into the dusking of the day in Bulgaria, Nov. 11, 2015. The U.S. troop's presence in Bulgaria is in support of Operation Atlantic Resolve. OAR provides U.S. Soldiers the opportunity to work with and train alongside our NATO allies, forge relationships that foster trust and mutual understanding, strengthen interoperability, and demonstrate the United States' commitment to the NATO Alliance. (U.S. Army photo by Staff Sgt. Steven Colvin)