Cpl. Tevfik Ozkaynak (left), a rifleman with Company C, 1st Battalion, 25th Marine Regiment, 4th Marine Division and Sgt. Lee Gugino (right), a squad leader, observe objective points on a map while on a reconnaissance patrol during exercise Riley Xanten II, in Burwash, Ontario, Feb. 3-5, 2017. During the exercise, the Marines joined soldiers from the Canadian Armed Forces to exchange knowledge and increase proficiency in cold weather tactics, survival skills, shelter building, ice fishing, and more. (U.S. Marine Corps photo by Sgt. Sara Graham/released) - Cpl. Tevfik Ozkaynak (left), a rifleman with Company C, 1st Battalion, 25th Marine Regiment, 4th Marine Division and Sgt. Lee Gugino (right), a squad leader, observe objective points on a map while on a reconnaissance patrol during exercise Riley Xanten II, in Burwash, Ontario, Feb. 3-5, 2017. During the exercise, the Marines joined soldiers from the Canadian Armed Forces to exchange knowledge and increase proficiency in cold weather tactics, survival skills, shelter building, ice fishing, and more. (U.S. Marine Corps photo by Sgt. Sara Graham/released)

Marines with 1st Battalion, 24th Marine Regiment, move down a road while the street is covered by an M1A1 Abrams tank during an assault on a simulated enemy town Aug. 17, 2014, aboard Camp Lejeune, N.C., during exercise Heavy Metal 14. As the assault continued, instructors and safety personnel would point out a Marine to play the role of a wounded casualty to assess the team’s casualty evacuation performance. - Marines with 1st Battalion, 24th Marine Regiment, move down a road while the street is covered by an M1A1 Abrams tank during an assault on a simulated enemy town Aug. 17, 2014, aboard Camp Lejeune, N.C., during exercise Heavy Metal 14. As the assault continued, instructors and safety personnel would point out a Marine to play the role of a wounded casualty to assess the team’s casualty evacuation performance.