Marines with Charlie Company, 1st Battalion, 24th Marine Regiment, 4th Marine Division, Marine Forces Reserve, position themselves to clear a building with suspected enemy insurgents at Exercise Arctic Eagle at Camp Grayling, Mich., April 25, 2015. The Marines, with an attachment of soldiers from the Danish Home Guard, simulated retaking a city from enemy insurgents at Camp Grayling's Combined Arms Collective Training Facility. (U.S. Marine Corps photo by Cpl. Ian Leones/Released) - Marines with Charlie Company, 1st Battalion, 24th Marine Regiment, 4th Marine Division, Marine Forces Reserve, position themselves to clear a building with suspected enemy insurgents at Exercise Arctic Eagle at Camp Grayling, Mich., April 25, 2015. The Marines, with an attachment of soldiers from the Danish Home Guard, simulated retaking a city from enemy insurgents at Camp Grayling's Combined Arms Collective Training Facility. (U.S. Marine Corps photo by Cpl. Ian Leones/Released)