Cpl. Dominic Sierra, a U.S. paratrooper assigned to Bulldog Troop, 1st Squadron, 91st Cavalry Regiment, 173rd Airborne Brigade, watches for opposing forces during a field exercise on Grafenwoehr Training Area, Germany, April 24, 2020. The 173rd Airborne Brigade is the U.S. Army’s contingency response force in Europe and routinely trains alongside NATO partners and allies.