U.S. Marines with 1st Battalion, 4th Marines, from Camp Pendleton, Calif., advance on an objective while participating in a mobile assault course event during 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 Master Sgt. John R. Nimmo, Sr./Released)