IV Corps (United States Army) is a corps-level military formation that serves under the United States Army Pacific command. The corps is headquartered at Joint Base Lewis-McChord, Washington. As one of the four numbered corps in the U.S. Army, IV Corps plays a crucial role in regional defense and joint and combined operations. Its primary mission is to prepare forces for deployment in response to contingencies worldwide. The Corps has a history dating back to World War II, having been reactivated during the Korean War and serving in various capacities since then, including significant roles during the Vietnam War, Operation Desert Storm, and the War in Afghanistan. IV Corps is composed of multiple divisions, brigades, and supporting units, with its forces organized for tactical flexibility to address a wide range of military missions.