The Battle of Khe Sanh was conducted in the Khe Sanh area of northwestern Quảng Trị Province, Republic of Vietnam, during the Vietnam War. The main US forces defending Khe Sanh Combat Base were two regiments of the United States Marine Corps supported by elements from the United States Army and the United States Air Force, as well as a small number of Army of the Republic of Vietnam troops. These were pitted against two to three divisional-size elements of the North Vietnamese People's Army of Vietnam.
The US command in Saigon initially believed that combat operations around KSCB during 1967 were part of a series of minor PAVN offensives in the border regions. That appraisal was later altered when the PAVN was found to be moving major forces into the area. In response, US forces were built up before the PAVN isolated the Marine base. Once the base came under siege, a series of actions was fought over a period of five months. During this time, KSCB and the hilltop outposts around it were subjected to constant PAVN artillery, mortar, and rocket attacks, and several infantry assaults. To support the Marine base, a massive aerial bombardment campaign was launched by the USAF.