Cpl. Tim Bracken, a fire team leader with Company A, 1st Battalion, 23rd Marine Regiment, 4th Marine Division, anticipates a night attack from 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 in the event of a crises that requires a rapid response. (U.S. Marine Corps photo by Cpl. Dallas Johnson/Released)