Lance Cpl. Jacob T. Campbell, an infantryman with 3rd Platoon, Company I, 3rd Battalion, 25th Marine Regiment, 4th Marine Division, Marine Forces Reserve, provides security for machine gunners at the infantry squad battle course during exercise Arctic Eagle at Camp Grayling, Mich., April 5, 2016. The Marines joined soldiers with the U.S. Army National Guard and the Danish Home Guard inthe bilateral exercise, designed to simulate a joint task force defending key infrastructure in the arctic region. (U.S. Marine Corps photo by Cpl. Ian Leones/Released)