A critical analysis of the conduct of the battle for Khe Sanh by the forces of the United States of America and the Peoples Army of Vietnam : a thesis presented in partial fulfilment of the requirements for the degree of Master of Philosophy in Defence and Strategic Studies at Massey University
From the 20th March – 8th April 1968 the 26th Marine Regiment of the 3rd Marine Division, and supporting elements was under siege at the Khe Sanh combat base and a number of surrounding fortified hilltop outposts in the northern Quang Tri Province of South Vietnam. The forces besieging the 26th Marines were those of General Vo Nguyen Giap's Peoples Army of Vietnam (PAVN), numbering some 17,300 troops. The 26th Marines were drawn into the siege of Khe Sanh through the desire of the General William Westmoreland, Commander of the Military Assistance Command Vietnam (MACV), to fix in place the regular divisions of the PAVN, and destroy them through the use of the superior firepower at the disposal of MACV within South Vietnam. Giap, realising Westmoreland's intentions utilised PAVN pressure on the 26th Marines at Khe Sanh, and other Allied positions throughout northern Quang Tri Province to convince Westmoreland that he intended to launch a major offensive into the province. In response to this, Westmoreland moved a significant number of his available forces north to counter this threat. With the MAVC forces concentrated in the north, this allowed Giap to launch the nationwide Tet Offensive on the 30th January 1968. Giap continued to apply pressure to the Marines at Khe Sanh, with a number of large-scale assaults on the Marine outposts that were defeated with the combined arms of the Marines, Army and the 7th Air Force. Political pressure from President Johnson, who feared a repeat of the defeat of the French at Dien Bien Phu in 1954, ensured all available assets were available to support the Marines. As MACV turned the tide of Giap's Tet Offensive, PAVN forces were withdrawn from the Khe Sanh Tactical Area Of Responsibility (TAOR), to support the offensive in the south of the country. Westmoreland directed the relief of Khe Sanh to be initiated on the 1st April 1968, with Operation Pegasus being initiated. Troops of the 1st Calvary Division (Airborne), 1st Marine Regiment, and the 3rd ARVN Airborne Task Force conducted road clearing and airmobile operations along National Route 9 (QL9) from Dong Ha to the Khe Sanh combat base, with the 26th Marines declared relieved on the 8th April 1968. Despite estimates that the PAVN suffered up to 15,000 casualties over the course of the siege, the PAVN forces were still able to deploy a similar number of troops within the Khe Sanh TAOR as prior to the siege, upon the closure of the combat base on the 17th June 1968.