U.S. Marines with Kilo Company, 3rd Battalion, 25th Marine Regiment, 4th Marine Division, look down-range during a simulated exercise of clearing a trench during Integrated Training Exercise 4-19 aboard the Marine Corps Air Ground Combat Center, Twentynine Palms, Calif., June 5, 2019. ITX 4-19 is a live-fire and maneuver combined arms exercise designed to train battalion and squadron-sized units in tactics, techniques and procedures required to provide a sustainable and ready operational reserve for employment across the full spectrum of crisis and global engagement. (U.S. Marine Corps photo by Lance Cpl. Preston L. Morris)