Army Lt. Col. Steven Gventer, commander of Battle Group Poland, explains the purpose of the Bull Run training exercise near Suwalki, Poland, July 16, 2017. The training, in accordance with NATO's enhanced Forward Presence initiative, allowed the unit to check its readiness and improve its interoperability as U.S., Polish, U.K. and Romanian soldiers worked side-by-side to carry out their allied mission. The U.S.-led Battle Group Poland is one of NATO's four multinational battle groups deployed as a deterrence force in the eastern part of the Alliance. Army photo by Spc. Kevin Wang