THE UNEXPLOITED VULNERABILITY OF THE MARINES AT KHE SANH

©2000 by Peter Brush

Like Ia Drang before it, both the North Vietnamese and the Americans declared victory at the battle of Khe Sanh in 1968. These dual claims of victory are not inappropriate in a tactical situation where the adversaries have different goals. At Khe Sanh, US commander General William C. Westmoreland was certain the Communists' primary goal was another Dien Bien Phu; namely, to isolate and capture the Marine combat base. The Communists, on the other hand, claimed that Khe Sanh was merely a diversion to draw US forces away from the populated areas of South Vietnam in order to maximize the effects of the Communists' efforts during the great Tet Offensive of 1968.

But the Communists were not completely rigid in their tactical thinking. Their diversionary claims notwithstanding, they would have captured the base at Khe Sanh had they been able.[1] The North Vietnamese, however, were unable to seize the base due to superior American firepower. They could have forced the Americans out of Khe Sanh, but they never realized the means by which this could have been done.

Both sides had compelling military reasons for their interest in the region around Khe Sanh. The geography of Indochina made Khe Sanh militarily significant. General Westmoreland felt the critical importance of Khe Sanh was clearly apparent. It would serve as a patrol base for the interdiction of enemy personnel and supplies coming down the Ho Chi Minh Trail from Laos into northern South Vietnam, a base for covert operations to harass the Communists along the Trail, the location of an airstrip for aerial reconnaissance of the Trail, the western anchor for the defensive line along the Demilitarized Zone (DMZ) separating North and South Vietnam, and a jumping-off point for a land invasion of Laos to cut the Ho Chi Minh Trail. According to Westmoreland, abandoning the US military presence at Khe Sanh would allow the People's Army of Vietnam (PAVN, the North Vietnamese Army or NVA) the ability to carry the fight into the populated coastal regions of Northern South Vietnam. For the Communists the region around Khe Sanh was the avenue for their entry into northern South Vietnam. From a strategic standpoint, it would clearly be in the best interests of the PAVN to end the American presence at Khe Sanh.[2]

Khe Sanh was located on Route 9 which ran from near the South China Sea at Dong Ha westerly to Savannaket, a market town in Laos along the Mekong River. This old French highway ran just south of and mostly parallel to the Demilitarized Zone. In August, 1967, Communist forces destroyed many of the bridges on Route 9, blocked the passes, and mined the highway. Khe Sanh was effectively isolated from overland resupply and would remain so for the next nine months. The Marine garrison at the Khe Sanh Combat Base could only be provisioned by air.

In October, 1967, General Giap ordered men and material sent down the Ho Chi Minh Trail and infiltrated across the Laotian-South Vietnam border in the vicinity of Khe Sanh. In response, General Westmoreland ordered the reinforcement of the Marine garrison there. Westmoreland wanted a large Marine force at Khe Sanh in order to entice PAVN troops into a killing zone where massive firepower would destroy them in large numbers. The limiting factor was that this force had to be small enough to be supplied by air. The result was a reinforced Marine regiment of about 6,600 men. On January 21, 1968, the PAVN began rocket, artillery, and mortar attacks on the Khe Sanh Combat Base. US air and artillery assets prevented the enemy from massing his forces in sufficient number to launch effective ground attacks on the base and surrounding hilltop positions. As long as Khe Sanh could be adequately supplied with ammunition, POL (petroleum, oil, lubricants) and food, the Marines could maintain their positions.

Concerns over the ability of the US to successfully defend Khe Sanh were manifest at the highest levels of government. President Lyndon B. Johnson, his national security advisor, the advisor's military assistant, and the National Security Council staff representative for Vietnam were all kept abreast of the developing situation around Khe Sanh. President Johnson summed up his feelings regarding Khe Sanh while the fighting was in progress: "I don't want any damn Dinbinphoo."[3] Both General Earl G. Wheeler, Chairman of the Joint Chiefs of Staff, and General Westmoreland assured the president that preparations for the defense of Khe Sanh were adequate and that the base would be successfully supplied.[4] Support for the defense of Khe Sanh received priority over all other operations in Vietnam.[5]

The job of supplying the Marine base at Khe Sanh fell to various Marine Corps and US Air Force aviation units. This airlift would have been a massive operation even under ideal circumstances. The purely logistical problems were compounded by poor visibility that fell below minimum requirements for airfield operations 40 percent of the time. The PAVN added to the difficulty by directing a heavy volume of antiaircraft and artillery fire at incoming aircraft.[6]

The resupply process suffered a sharp setback on February 10 when PAVN gunners shot up a Marine C-130, fully laden with fuel bladders, while it was attempting a landing at the Khe Sanh airstrip. As a result of this incident and fire damage sustained by other aircraft already on the ground, C-130 landings were temporarily suspended during February. At the beginning of March this suspension was made permanent. Consequently, during these periods, the Marines were denied the use of the best heavy-lift aviation assets in their inventory. Most supplies thereafter were delivered by parachute. According to the official Marine Corps history of the battle of Khe Sanh, these parachute drops ". . . were sufficient for bulk commodities such as rations and ammunition."[7] Certain supplies, such as replacement troops, medical evacuations and medical supplies, could only be delivered by aircraft that made actual landings on the runway at Khe Sanh.

In the opinion of this writer, who was present during the siege, this official assessment of the success of US supply capabilities regarding rations was overly optimistic. A hot meal was defined as heated C-rations; the Marines at Khe Sanh sometimes went weeks without hot meals. Rations were routinely limited to two meals per man per day. One Marine reported that he went several days with only one C-ration meal per day.[8] A company commander on Hill 861, located about two miles northwest of the combat base, reported his men were forced to go for days without water.[9] Another reported that his water ration was one-half canteen cup of water per day, which had to suffice for drinking, shaving, and brushing teeth.[10]

Water is an extremely difficult commodity to deliver to a besieged garrison. It is heavy, it must be handled in special containers that cannot be used for the delivery of other liquids, and water containers are vulnerable to incoming artillery attacks. One helicopter crew attempting to deliver water to Hill 861 was rattled by PAVN fire, panicked, and released its cargo from a height of two hundred feet. The parched Marines watched the water containers burst apart in mid-air.[11]

Had the Communists realized the vulnerability of the Marine water supply, they could have forced the abandonment of the combat base. The Marines occupied various hilltop positions surrounding Khe Sanh. These positions, initially supplied from the combat base itself, were later provisioned by helicopters flying from the 3d Marine Division Forward base at Dong Ha. Water for the combat base came from the small Rao Quan River which flowed through hills to the north occupied by the PAVN.

Even though the combat base was not dependent on air-lifted water as the hill positions were, it was, nevertheless, often a scarce commodity. The water point itself was located about 150 meters outside the northern sector of the base perimeter. There was a small hill and tall grass that obscured visual contact with the water point. The water was lifted ninety feet over an 800-foot span by pumps. A dirt dam twenty-five meters wide caused the formation of a reservoir six feet deep. During the extensive rains of September and October, 1967, the dam broke. US Navy EO1 (Equipment Operator First Class) Rulon V. Rees led a detail to repair the dam in the fall of 1967 using old scrapped Marston matting from the airstrip. This detail blasted a crater in the river bed about thirty feet in front of the dam to act as a reservoir in case the river level fell. Marston matting was placed on the face of the dam.

No patrols went out to get the water. It was pumped inside the perimeter and went to a large black rubber water tower container. This reservoir was frequently punctured during the siege, causing temporary lack of water on the base.[12]

Had the PAVN realized how vulnerable the Marines' water supply was, they could have interdicted it by diverting the Rao Quan River or contaminating it, thereby forcing the Marines to attempt a breakout.[13] However, General Giap, who achieved victory at Dien Bien Phu in part due to his meticulous battlefield planning, seems to have not realized the vulnerability of the Marines' water supply. Nor did the local PAVN commander. General Westmoreland did not become aware of the magnitude of the potential water problem until the base was surrounded by the North Vietnamese. By that time, a successful evacuation was not possible.

The concept of an overland evacuation of a reinforced regiment, fighting its way through two or three PAVN divisions that held every tactical advantage, presented a problem of such magnitude that Westmoreland was reluctant to consider it. The Joint Chiefs refused to consider it.

Had the PAVN succeeded in interdicting the combat base's water supply, 3rd Marine Division commander General R. M. Tompkins is quoted in one source as saying that it would have been impossible to provision Khe Sanh with water in addition to its other resupply requirements.[14] However, in a letter to General Davidson, General Tompkins stated that water could have been added to the provisions already being supplied to support the base. By examining the supply requirements and the logistical capabilities of the Americans it is possible to determine which of these contradictory statements is correct.

III Marine Amphibious Force (III MAF) headquarters established the official supply requirement for Khe Sanh at 235 tons per day. The Americans were hard pressed to meet these requirements. The airstrip was completely closed on various occasions due to the weather or damage sustained from enemy fire. During the month of February alone, the combat base had a deficit of 1,037 tons of supplies actually delivered compared to scheduled deliveries. The air delivery problems were compounded when the use of the large C-130 cargo planes was curtailed due to hostile fire. Passenger requirements were met by the use of C-123 aircraft. The smaller capacity of the C-123's necessitated a five-fold increase in landings. More landings meant more targets; one aircraft upon returning to Da Nang was found to contain 242 holes before the maintenance personnel gave up counting. In the first month of the siege four major aircraft were lost to hostile fire.[15]

Helicopters were widely used as resupply vehicles. Only helicopters could reach the hilltop positions, whose supply requirements were 32,000 pounds per day. Helicopters were stationed at the combat base at the beginning of the fighting. These aircraft became so vulnerable to hostile fire that they had to be kept constantly in the air whether they had missions to perform or not. Eventually losses became so great that this unit was deployed away from Khe Sanh, as helicopters were being lost at a rate faster than they could be replaced. No less than thirty-three helicopters were destroyed or permanently disabled between the beginning of the siege and the end of March, 1968.[16]

These losses were sustained without the implementation of an additional requirement for water delivery. According to the relevant US Army field manual, the water supply requirement for drinking, personal hygiene, food preparation, laundry, and medical treatment is six pounds of water per man per day. These levels provide enough water to support continuous combat operations for extended periods.[17] The implementation of this requirement would have added 158 tons per day, an additional load of 67% over the supply requirement without water. Unlike ammunition and food rations, which could be palletized and delivered by parachute without the need for special containers, water was difficult to stockpile during the periods when resupply was possible, for use when landings were not permitted due to weather or hostile fire. The official optimism of US commanders regarding resupply at Khe Sanh notwithstanding, the Americans would not have been able to provide the base with water under the existing tactical conditions.

By March the PAVN began withdrawing from the Khe Sanh area, and in April the Marine regiment was replaced, allowing it to withdraw via the newly reopened Route 9. The primary goal of the American forces at Khe Sanh was to destroy large numbers of North Vietnamese soldiers. In this they were successful. Although the official body count of enemy soldiers killed at Khe Sanh was 1,602, the US command placed the total number of North Vietnamese at between 10,000 and 15,000 killed in action. American deaths sustained in the siege itself, plus mobile operations in the Khe Sanh tactical area after the siege, totaled approximately 1,000 KIA.[18] In a war that focused on kill ratios and body counts as a measure of success, Khe Sanh was placed in the win column by the American military.

As with the Americans at Khe Sanh, the French garrisoned Dien Bien Phu as "bait" for the Vietnamese Communist forces. An American observer there reported that the French base could "withstand any kind of attack the Viet Minh are capable of launching."[19] When the Viet Minh knocked out the airfield at Dien Bien Phu, resupply became impossible and the French became isolated and vulnerable. On May 7, 1954, after sustaining heavy losses, the French were forced to surrender. The very next day the Indochina phase of the Geneva Conference began. France's loss at Dien Bien Phu led directly to their withdrawal from Indochina.

Victory in combat, however defined, often hangs by a tenuous thread. Even with the claim of victory by the US at Khe Sanh and during the Tet 1968 fighting in general, the psychological victory of the Vietnamese Communists during this period led to the beginning of the end for the United States in Vietnam. It was during the 1968 Tet Offensive that opposition in the US to the war in Vietnam, in terms of regarding involvement as a mistake, first rose above 50 percent and exceed the level of support. Approximately one fourth of all the television film reports on the evening news programs in the US during February and March, 1968, were devoted to portraying the situation of the Marines at Khe Sanh.[20] Had the North Vietnamese simply interdicted the water supply of the Marines at the Khe Sanh Combat Base in 1968, thereby forcing the Marines to evacuate and inflicting heavy casualties upon them in the process, the United States could have easily have met a fate similar to that of the French.

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[1] I am indebted to Professor Cecil B. Currey, Professor of Military History at the University of South Florida and Chaplain (Colonel), USAR (Ret.), for this interpretation. Colonel Currey has interviewed and corresponded with Vietnamese Senior General Vo Nguyen Giap. According to Currey, Giap planned Khe Sanh primarily as a diversion but also thought the fighting there could have resulted in a second Dien Bien Phu. Personal communication from Colonel Currey to the author dated 11 April, 1994.

[2] General William C. Westmoreland, A Soldier Reports, (Garden City, N.Y.: 1976), p. 336.

[3] Time magazine, February 9, 1968, p. 16.

[4] John Prados and Ray W. Stubbe, Valley of Decision, (Boston, MA: Houghton Mifflin, 1991), pp. 289-290.

[5] Captain Moyers S. Shore II, The Battle for Khe Sanh, (Washington, D.C.: History and Museums Division, Headquarters, U.S. Marine Corps, 1969), p. 93.

[6] Shore, p. 74.

[7] Shore, p. 79.

[8] Prados and Stubbe, p. 282.

[9] Robert Pisor, The End of the Line, (N.Y.: Ballantine Books, 1982), p. 188, 199, and personal recollection of the author.

[10] Prados and Stubbe, p. 306.

[11] Shore, p. 199.

[12] I am indebted to Ray W. Stubbe, Lutheran chaplain of the 1st Battalion, 26th Marines at Khe Sanh, for this description of the water source. It was taken from Stubbe's diary written during the siege. Personal correspondence from Stubbe to the author dated March 21, 1994.

[13] Westmoreland's intelligence chief, General Phillip B. Davidson, USA (Ret.) notes that it was not benevolence on the part of the PAVN that kept them from poisoning the water supply. According to the Geneva Protocol of 1925, which the North Vietnamese ratified in 1957, the chemical pollution of a stream is permitted as long as the stream is only used by military personnel. The Rao Quan served no civilians and legally could have been poisoned. Vietnam at War, (Novato, CA: Presidio Press, 1988), pp. 568-569.

[14] Prados and Stubbe, p. 364. Pisor, p. 202. Pisor's quotation from General Thompkins is taken from an official Marine Corps Oral History collection published in 1973. General Davidson notes that Thompkins felt at the time he wrote to Davidson and at the time of the siege that the base could have been provisioned with water by airlift. These contradictory claims remain inexplicable to this writer. Davidson, p. 569.

[15] Prados and Stubbe, p. 373, 374, 375, 390. Peter C. Rollins, "Television's Vietnam: The Visual Language of Television News," Journal of American Culture, 4 (1981), p. 123.

[16] Prados and Stubbe, p. 381, 382, 391.

[17] FM 101-10-1-1/2, Staff Officers' Field Manual Organizational, Technical, and Logistical Data Planning Factors (Vol. 2), (Washington, D.C.: Headquarters, Dept. of the Army, 1987), p. 2-8 & 2-9.

[18] Pisor, p. 237; Prados and Stubbe, p. 451, 454.

[19] Report of Special U.S. Mission to Indochina, February 5, 1954, Eisenhower Papers, "Cleanup" File, Box 16, quoted in George C. Herring and Richard H. Immerman, "Eisenhower, Dulles, and Dienbienphu: 'The Day We Didn't Go to War' Revisited," in Journal of American History, Vol. 71, No. 2, Sept 1984, p. 345.

[20] Leslie H. Gelb and Richard K. Betts, The Irony of Vietnam: The System Worked, (Washington, D.C.: Brookings, 1979), p. 160. Don Oberdorfer, Tet!, (N.Y.: Avon, 1971), p. 258.