Reserve Marines with Company A, 1st Battalion, 23rd Marine Regiment, 4th Marine Division, position themselves in a foxhole prior to engaging a notional enemy during an air assault course, at Integrated Training Exercise 4-18, aboard Marine Corps Air Ground Combat Center Twentynine Palms, Calif., June 17, 2018. ITX 4-18 provides Marine Air-Ground Task Force elements an opportunity to undergo service-level competency assessments so that they can seamlessly integrate with active duty Marines, into a Marine Air Ground Task Force, in the event of a crises that requires a rapid response. (U.S. Marine Corps photo by Cpl. Dallas Johnson/Released)