Maj. Gen. Duane A. Gamble, commander, 21st Theater Sustainment Command since June 24, 2015, speaks with Estonian allies during a tour of Tapa Army Base, Estonia, July 9, as part of Operation Atlantic Resolve. American Soldiers train side-by-side with NATO allies as part of Operation Atlantic Resolve to demonstrate their continued commitment to collective security through a series of actions designed to reassure NATO allies and partners of America's dedication to enduring peace and stability in Europe. (U.S. Army photo by Spc. Jacqueline Dowland, 13th Public Affairs Detachment)