Vietnam War: Battle of Khe Sanh

Color photograph of helicopters and soldiers during the Battle of Khe Sanh, Vietnam War.

Tommy Truong79/Flickr/CC BY 2.0

The Siege of Khe Sanh occurred during the Vietnam War. The fighting around Khe Sanh began January 21, 1968, and concluded around April 8, 1968.

Armies and Commanders


North Vietnamese

Battle of Khe Sanh Overview

In the summer of 1967, American commanders learned of a build-up of the People's Army of North Vietnam (PAVN) forces in the area around Khe Sanh in northwest South Vietnam. Responding to this, the Khe Sanh Combat Base (KSCB), located on a plateau in a valley of the same name, was reinforced by elements of the 26th Marine Regiment under Colonel David E. Lownds. Also, outposts on the surrounding hills were occupied by American forces. While KSCB possessed an airstrip, it's overland supply route was over the dilapidated Route 9, which led back to the coast.

That fall, a supply convoy was ambushed by PAVN forces on Route 9. This was the last overland attempt to resupply Khe Sanh until the following April. Through December, PAVN troops were spotted in the area, but there was little fighting. With the increase in enemy activity, a decision was needed regarding whether to further reinforce Khe Sanh or abandon the position. Assessing the situation, General William Westmoreland elected to increase the troop levels at KSCB.

Though he was supported by the commander of the III Marine Amphibious Force, Lieutenant General Robert E. Cushman, many Marine officers disagreed with Westmoreland's decision. Many believed that Khe Sanh was not necessary for the ongoing operations. In late December/early January, intelligence reported the arrival of the 325th, 324th, and 320th PAVN divisions within striking distance of KSCB. In response, additional Marines were moved to the base. On January 20, the PAVN defector alerted Lownds that an attack was imminent. At 12:30 a.m. on the 21st, Hill 861 was attacked by about 300 PAVN troops and KSCB was heavily shelled.

While the attack was repulsed, the PAVN soldiers did manage to breach the Marine defenses. The attack also revealed the arrival of the 304th PAVN division in the area. To clear their flank, PAVN forces attacked and overran Laotian troops at Ban Houei Sane on January 23, forcing the survivors to flee to the U.S. Special Forces camp at Lang Vei. During this time, KSCB received its last reinforcements: additional Marines and the 37th Army of the Republic of Vietnam Ranger Battalion. Enduring several heavy bombardments, the defenders at Khe Sanh learned on January 29 that there would be no truce for the upcoming Tet holiday.

To support the defense of the base, which had been dubbed Operation Scotland, Westmoreland initiated Operation Niagara. This action called for the massive application of aerial firepower. Utilizing a variety of advanced sensors and forward air controllers, American aircraft began pounding PAVN positions around Khe Sanh. When the Tet Offensive commenced on January 30, the fighting around KSCB quieted. Fighting in the area resumed on February 7, when the camp at Lang Vei was overrun. Fleeing from the scene, Special Forces units made their way to Khe Sanh.

Unable to resupply KSCB by land, American forces delivered needed materials by air, dodging an intense gauntlet of PAVN anti-aircraft fire. Ultimately, tactics such as the "Super Gaggle" (which involved the use of A-4 Skyhawk fighters to suppress ground fire) allowed helicopters to resupply the hilltop outposts while drops from C-130s delivered goods to the main base. On the same night that Lang Vei was attacked, PAVN troops assaulted an observation post at KSCB. In the last week of February, fighting intensified when a Marine patrol was ambushed and several attacks were launched against the 37th ARVN's lines.

In March, intelligence began noticing an exodus of PAVN units from the vicinity of Khe Sanh. Despite this, shelling continued and the base's ammunition dump detonated for the second time during the campaign. Pressing out from KSCB, Marine patrols engaged the enemy on March 30. The next day, Operation Scotland was ended. Operational control of the area turned over to the 1st Air Cavalry Division for the execution of Operation Pegasus.

Designed to "break" the siege of Keh Sanh, Operation Pegasus called for elements of the 1st and 3rd Marine Regiments to attack up Route 9 towards Khe Sanh. Meanwhile, the 1st Air Cavalry moved by helicopter to seize key terrain features along the line of advance. As the Marines advanced, engineers worked to repair the road. This plan infuriated the Marines at KSCB, as they did not believe they needed to be "rescued." Jumping off on April 1, Pegasus met little resistance as American forces moved west. The first major engagement occurred on April 6, when a day-long battle was waged against a PAVN blocking force. Fighting largely concluded with a three-day fight near Khe Sanh village. Troops linked up with the Marines at KSCB on April 8. Three days later, Route 9 was declared open.


Lasting 77 days, the siege of Khe Sanh saw American and South Vietnamese forces suffer. In the end, there were 703 killed, 2,642 wounded, and 7 missing. PAVN losses are not known with accuracy but are estimated at between 10,000 to 15,000 dead and wounded. Following the battle, Lownds' men were relieved and Westmoreland ordered the base occupied until he left Vietnam in June. His successor, General Creighton Abrams, did not believe that retaining Khe Sanh was necessary. He ordered the base destroyed and abandoned later that month. This decision earned the ire of the American press, who questioned why Khe Sanh had to be defended in January but was no longer needed in July. Abrams' response was that the then-current military situation no longer dictated that it be held. To this day, it is unclear whether PAVN leadership in Hanoi intended to fight a decisive battle at Khe Sanh, or if operations in the area were meant to distract Westmoreland in the weeks before the Tet Offensive.


  • Brush, Peter. "Battle of Khe Sanh: Recounting the Battle's Casualties." HistoryNet, June 26, 2007.
  • Unknown. "The Siege at Khe Sanh." PBS.
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Your Citation
Hickman, Kennedy. "Vietnam War: Battle of Khe Sanh." ThoughtCo, Apr. 5, 2023, Hickman, Kennedy. (2023, April 5). Vietnam War: Battle of Khe Sanh. Retrieved from Hickman, Kennedy. "Vietnam War: Battle of Khe Sanh." ThoughtCo. (accessed June 5, 2023).