U.S. Marines operate an M1A1 Abrams tank during a mechanized assault course in support of Integrated Training Exercise 2-15 at Marine Corps Air Ground Combat Center Twentynine Palms (MCAGCC), Calif., Feb. 4, 2015. MCAGCC conducts relevant live-fire combined arms training, urban operations, and Joint/Coalition level integration training that promotes operational forces readiness. (U.S. Air Force photo by Staff Sgt. Amy F. Picard/Released)