CAMP GRAYLING, Mich. -- A Marine with 4th Assault Amphibian Battalion, 4th Marine Division, Marine Forces Reserve, provides security for his amphibious assault vehicle at Camp Grayling Joint Maneuver Training Center, Mich., Aug. 17, 2016. The exercise also included infantry training techniques and military operations in urban terrain. Exercise Northern Strike Northern Strike 16 is a National Guard Bureau-sponsored exercise uniting approximately 5,000 Army, Air Force, Marine, and Special Forces service members from 20 states and three coalition countries. The exercise strives to provide accessible, readiness-building opportunities for military units from all service branches to achieve and sustain proficiency in conducting mission command, air, sea, and ground maneuver integration, and the synchronization of fires in a joint, multinational, decisive action environment. (U.S. Marine Corps photo by Cpl. Devan Alonzo Barnett/Released)