Primary Sources: Vietnam War

The Battle of Khe Sanh (21 January – 9 July 1968) was conducted in the Khe Sanh area of northwestern Quảng Trị Province, Republic of Vietnam (South Vietnam), during the Vietnam War. The main US forces defending Khe Sanh Combat Base (KSCB) were two regiments of the United States Marine Corps supported by elements from the United States Army and the United States Air Force (USAF), as well as a small number of Army of the Republic of Vietnam (ARVN) troops. These were pitted against two to three divisional-size elements of the North Vietnamese People's Army of Vietnam (PAVN).

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 were 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 (Operation Niagara) was launched by the USAF. Over 100,000 tons of bombs were dropped by US aircraft and over 158,000 artillery rounds were fired in defense of the base. Throughout the campaign, US forces used the latest technology to locate PAVN forces for targeting. Additionally, the logistical effort required to support the base once it was isolated demanded the implementation of other tactical innovations to keep the Marines supplied.

In March 1968, an overland relief expedition (Operation Pegasus) was launched by a combined Marine–Army/ARVN task force that eventually broke through to the Marines at Khe Sanh. American commanders considered the defense of Khe Sanh a success, but shortly after the siege was lifted, the decision was made to dismantle the base rather than risk similar battles in the future. On 19 June 1968, the evacuation and destruction of KSCB began. Amid heavy shelling, the Marines attempted to salvage what they could before destroying what remained as they were evacuated. Minor attacks continued before the base was officially closed on 5 July. Marines remained around Hill 689, though, and fighting in the vicinity continued until 11 July until they were finally withdrawn, bringing the battle to a close. Wikipedia