U.S. Marine Corps Maj. Brian Greene, 5th Marine Regiment Operations Officer, describes points on a terrain model during an brief in support of Exercise STEEL KNIGHT 2014 aboard Marine Corps Air Ground Combat Center Twentynine Palms, Calif., Dec. 12 2013. Steel Knight enables 1st Marine Division to test and refine its command and control capabilities by acting as the headquarters element for a forward-deployed Marine Expeditionary force. (U.S. Marine Corps photo by Cpl. Justin A. Bopp, 1st Marine Division Combat Camera / Released)