British Pvt. Adele Frost (center), a medic with 3rd Princess of Wales Royal Regiment, and U.S. Marine Corps Sgt. Jacob Mueller (left) and Sgt. Jordan Hensley (left) squad leaders with Kilo Company 3rd Battalion, 25th Marine Regiment, participate in a land navigation course at Exercise Northern Strike in Camp Grayling, Mich., Aug. 6, 2018. Exercise Northern Strike is a National Guard Bureau-sponsored training exercise that unites service members from multiple branches, states and coalition countries to conduct combined ground and air combat operations. (U.S. Marine Corps photo by Cpl. Niles Lee)