U.S. Marines Col. Benjamin T. Watson, left, the commanding

U.S. Marines Col. Benjamin T. Watson, left, the commanding officer of Marine Barracks Washington, Sgt. Maj. Micheal P. Barrett, second left, Sgt. Maj. Ronald L. Green, third left, Commandant of the Marine Corps Gen. Joseph F. Dunford, Jr., fourth left, and other guests listen to the invocation during the relief and appointment ceremony at the Marine Corps War Memorial, Arlington, Va., Feb. 20, 2015. Dunford relieved Barrett and appointed Green as the 18th sergeant major of the Marine Corps. (U.S. Marine Corps photo by Sgt. Gabriela Garcia/Released)