A U.S. Marine assigned to G Company, 2nd Battalion, 1st Marines, Battalion Landing Team, 31st Marine Expeditionary Unit (MEU), engages the simulated enemies during a mechanized raid in Tinian, Guam, on Sept. 13, 2012. The Marines are conducting the raid as a part of the 31st MEU's certification exercise 2012. (U.S. Marine Corps photo by LCpl Caleb Hoover/Released)