From January to April 1968, the battle at Khe Sanh, perhaps the most controversial of the Vietnam War, raged for 77 days. The two opposing commanders, Generals William C. Westmoreland and Vo Nguyen Giap, used the Khe Sanh combat base and surrounding area for their own purposes. For Westmoreland, Khe Sanh evolved from a reconnaissance platform to a potential invasion launch point, to a strongpoint and, finally, to a killing ground. For Giap, the base was a testing ground and then a staging ground for an option play. Each general knew the other had plans for the area, and at times each thought he was manipulating the other. In the end, Khe Sanh became the point at which two strategies of two generals converged.

As early as 1964 Westmoreland described Khe Sanh’s possibilities: ‘Khe Sanh could serve as a patrol base blocking enemy infiltration from Laos; a base for SOP operations to harass the enemy in Laos; an airstrip for reconnaissance to survey the Ho Chi Minh Trail; a western anchor for the defenses south of the DMZ; and an eventual jumping-off point for ground operations to cut the Ho Chi Minh Trail.’

The prospects Westmoreland saw for Khe Sanh changed through the course of the war. Intelligence had been the primary reason for being at Khe Sanh in 1964, in the early stages of the war. In fact, recon forces from the base were the first to confirm that Main Force NVA units were operating inside South Vietnam. By 1966, Westmoreland had begun to consider Khe Sanh as part of a larger strategy. ‘I still hoped some day to get approval for a major drive into Laos to cut the Ho Chi Minh Trail,’ he said, ‘in which case I would need Khe Sanh as the base for the operation.’ In a meeting with Lt. Gen. Lewis Walt, commander of III Marine Amphibious Force (MAF), Westmoreland said that he placed great strategic importance on Khe Sanh. He believed it was absolutely essential to hold the base, which explains why he then ordered Marines there. In September 1966 MACV began detailed planning for an invasion into Laos, and an airfield was built at Khe Sanh in October.

In April 1967 two strategic options were pitched to President Lyndon B. Johnson: one by Westmoreland, to enter Laos; and one by adviser Walt Rostow, to invade North Vietnam just above the DMZ. Although both were rejected, Westmoreland never gave up hope, and from August to October he upgraded the airfield at Khe Sanh so that it could serve as the advance base for a Laotian invasion. As soon as the airfield reopened, he began to stockpile supplies for the invasion.

By mid-1967, however, Khe Sanh’s role had changed. Its primary role was still strategic, but it was now being used as a defensive strongpoint as well. When Defense Secretary Robert McNamara proposed erecting a DMZ barrier in 1966, Khe Sanh became part of it, as the westernmost point in what Westmoreland called ‘the strong point obstacle system.’ Khe Sanh was designated as one of the Marine strongpoints south of the DMZ. According to Westmoreland: ‘The Marines devised these strong points to serve as observation posts, patrol bases and fire support bases. They were meant to canalize Communist movements. It was an effort to counter both enemy infiltration and direct invasion by increasing the enemy’s cost and minimizing our own.’

Lieutenant General Robert Cushman, new commander of III MAF, saw Khe Sanh as part of a shield below the DMZ for pacification in Quang Tri province. So while Westmoreland still hoped to use Khe Sanh in an offensive capacity, it was fit into a defensive scheme for I Corps. Hanoi’s attacks into I Corps in 1966 and 1967, as perceived by Westmoreland, gave an added defensive dimension to Khe Sanh. The base and its adjacent outposts commanded the main avenue of approach into eastern Quang Tri and, as Westmoreland saw it, formed a solid block to an enemy invasion or motorized supply from the west. Westmoreland feared that the two northern provinces of I Corps would be the target of an invasion.

Westmoreland’s extremely strong belief that North Vietnam intended to seize parts of I Corps is well-documented. His longtime intelligence chief, Lt. Gen. Phillip Davidson, commented in his postwar book Vietnam at War that the fear that the VC/NVA would take over a part of South Vietnam and establish a government was a long-standing obsession of General Westmoreland’s. After observing the enemy’s situation in early 1966, Westmoreland concluded that the North Vietnamese intended to open a new front in northern I Corps and hoped to seize and hold the northern areas as a base for a so-called ‘liberation regime’ that could be parlayed into a winning compromise in future talks. Westmoreland guessed correctly. During the Tet Offensive at Hue in 1968, the Communists formed a revolutionary government called the New Alliance for National Democratic and Peace Forces. In a postwar interview, retired Brig. Gen. Richard S. Sweet confirmed the Communists’ intent in I Corps. He said that during Tet his unit, the 2nd Battalion, 12th Cavalry, captured a large group outside Hue that turned out to be the provisional government supposed to govern that area of Vietnam once it was captured by the Communists.

In February 1966, still leery of enemy intent, Westmoreland said to President Johnson at the Honolulu conference, ‘If I were Giap I would take Hue.’ When the A Shau Valley Special Forces camp was captured in March, it appeared that perhaps his prediction would come true. Westmoreland believed that the capture of the Special Forces camp was a clue to the enemy’s future plans. The general always viewed enemy actions in light of how they aided the Communist goal of seizing the northern provinces. To forestall an invasion, MACV launched Operation Hastings south of the DMZ in July 1966. By the end of 1966, the Communists had increased their maneuver battalions (infantry, armor and artillery) in I Corps from 26 to 45, most of which were NVA units. To defend I Corps, Westmoreland shifted more units into the area. By mid-1967, the allied forces outnumbered the NVA/VC units 86 to 54. But only two of these maneuver battalions were stationed at Khe Sanh, since it was just one of the strongpoints south of the DMZ.

While Westmoreland was pondering the invasion of Laos in early 1966, the Hanoi leadership determined that its strategy of protracted warfare using mostly irregular units had been stalemated on the battlefield. This led to a fundamental strategy change. As Don Oberdorfer says in Tet!: The Turning Point in the Vietnam War, dur-ing the First Indochina War the Lao Dong Party had brilliantly coordinated military and diplomatic strategy to convince the French it would be madness to continue their struggle. The North Vietnamese leaders in 1966 believed it was necessary to move into a similar phase of simultaneous negotiating and fighting.

In April 1966 NVA General Nguyen Van Vinh explained to members of the Central Office of South Vietnam (COSVN) at a secret meeting that the situation had changed. The first stage of the war, the fighting stage, during which the Americans had the advantage, was in progress. Then, he said, during the fighting-while-negotiating stage and ‘the stage where negotiations are made and treaties are signed,’ the Communists would have the advantage over the Americans, who were unskilled at diplomatic and political warfare. The operation was called the ‘General Offensive/General Uprising’ and included plans to launch an offensive against South Vietnamese cities and then get the citizens to join the Northern Communists in an uprising.

The general explained: ‘Fighting continues until the emergence of a situation where both sides are fighting indecisively. Then a situation where fighting and negotiations are conducted simultaneously may emerge.’ The Communist leaders in Hanoi officially determined that the next phase would begin. This decision was passed on to the National Liberation Front.

Ba Tra, deputy chief and operating leader of what was known as the ‘Intellectual Proselytizing Section’ for Saigon, at a conference in War Zone D, learned that the fighting-and-negotiating phase of the war would begin at the end of 1967. In July 1967 Resolution 13 was issued from Hanoi and passed on to the South, officially adopting this strategy. It also called for an offensive in early 1968. Giap, however, opposed the idea of an offensive against the American-led forces. He believed the greatest threat to North Vietnam would be an invasion by the United States. He especially feared an invasion just north of the DMZ. General Giap believed that an attack northward was Westmoreland’s only logical next step. He also thought the United States planned to invade Laos to cut the Ho Chi Minh Trail, either in conjunction with an invasion of the North or as an entirely separate campaign. In an article published in September 1967, Giap wrote that his major concern was that the United States would expand the conflict beyond South Vietnam’s borders, and that an American landing in North Vietnam might have disastrous consequences for the North Vietnamese regime. Because he had originally opposed it, Giap had not been given command of the offensive, but with the death of General Nguyen Chi Thanh, Giap became its architect and commander.

Nonetheless, Giap insisted that the defense of North Vietnam held top priority, regardless of any other actions by the Communist forces. Robert Pisor, in The End Of The Line: A Narrative History of the Siege of Khe Sanh, describes Giap’s preparations for an allied invasion of North Vietnam: ‘He prepared his people and his armed forces for invasion. Nearly 300,000 soldiers of the People’s Army were at home, arrayed in depth to receive the Americans. Every hamlet and village had many bunkers, trenches, and fighting positions. Even schoolgirls took bayonet drill.’

The North Vietnamese forces were ready, but Giap and Hanoi still had to determine what the Americans planned to do. Hanoi needed to know how the United States would respond to a Communist buildup and offensive. If Communist movements triggered a U.S. counterattack into North Vietnam or Laos, then the NVA must be ready to respond, and Giap would be able to terminate the General Offensive/General Uprising at that moment and revert to a defensive posture. He needed to test Westmoreland’s as well as Washington’s response. He decided to launch attacks near the DMZ. The U.S. response to this tactical phase would help Giap formulate and develop the offensive he was to command.

The battles along the DMZ near Cam Lo, Khe Sanh, Con Thien, Camp Carroll, Quang Tri city, the Rockpile and Route 9, from March to August 1967, served as the test. During this time, Giap placed five NVA divisions and three NVA regiments near or in Quang Tri. Westmoreland responded to the assaults with more units and firepower in I Corps. The NVA soldiers incurred heavy losses, but when Westmoreland did not send U.S. troops into either North Vietnam or Laos, Hanoi believed the United States would continue to react only defensively.

Later in 1967, Giap ordered the initiation of the winter-spring campaign, with Phase I to last from October to December. The campaign included the famous ‘border battles’ at Loc Ninh (in III Corps) and Dak To (in II Corps), designed to divert U.S. attention away from the vulnerable northern provinces of I Corps. Thus the DMZ battles and the border battles were fought for entirely different purposes–the former was to test the American response, the latter to act as a diversion. The midyear Communist assaults on the Khe Sanh base were part of Vo Nguyen Giap’s test scenario. The attacks were not meant to be a diversion, nor had Giap intended for the action to escalate into a battle like Dien Bien Phu.

North Vietnam’s strategic goals and objectives for 1968, to which Giap tailored the offensive, had been established by a series of resolutions. Resolution 13 had discussed the objective of the new fighting-negotiating phase: ‘The strategic objective was to insist upon a coalition government. Once success was achieved politically, such a government would…initiate negotiations with the United States to solve pending political and military matters in the event of victory.’

The resolution was sent to Communist leaders in the South. In August the fighting-while-negotiating strategy was discussed at the NLF’s Third Congress, which espoused a new political program, ‘the creation of a coalition government’ to use as a negotiating chip during the next phase. In October Hanoi spelled out its objectives for the planned offensive in the ‘Quang Trung Resolution’ (Resolution 14): ‘The upcoming General Offensive/General Uprising will be a period, a process, of intensive and complicated strategic offensives by the military, political, and diplomatic means…a process in which we will attack and advance on the enemy continuously both militarily and politically.’

Documents from Hanoi translated by Captain Ronnie E. Ford, an Army intelligence officer, revealed for the first time the precise details of the three phases of the Tet Offensive. In the February 1995 issue of Vietnam, Ford summarized the phases. In Phase I, October to December 1967, the NVA/VC would mass forces and conduct battles along the border regions of the Central Highlands to attract U.S. units and allow VC units to infiltrate into the cities to prepare themselves and South Vietnam’s population for the General Uprising. Dur-ing Phase II, January to March 1968, the General Offensive/General Uprising would begin. The VC would launch attacks on the cities and military bases and appeal to South Vietnam’s population to join the General Uprising. Concurrently, diplomatic efforts would be underway calling for both negotiations and the recognition of a Southern coalition government. In Phase III, the NVA would cross the DMZ to assault American units surrounded by the uprising. A second wave of troops would move into the lowland areas, creating the conditions necessary for victory. Hanoi would hold all the negotiating chips as they headed into the fighting-while-negotiating phase.

Phase III was dependent upon the results of Phase II and the purpose and positioning of the NVA in Phase II, because all would have an impact on the situation at Khe Sanh. Without having the advantage of seeing the declassified Vietnamese documents at the time, General Davidson interpreted the first two phases correctly in Vietnam at War, but he believed that the third phase would include a set-piece battle as the grand finale. The Americans predicted this would occur at Khe Sanh and believed that an all-out single attack would put final victory before talks.

The Route 9 Front (equal to a U.S. Army corps) was the most important force in North Vietnam’s plan. Giap wanted to test America’s strategic intentions one final time before the green light was given for the Tet Offensive (Phase II). Giap decided to place the front at the juncture of Laos and North and South Vietnam. If a corps-size presence did not trigger a U.S. invasion of North Vietnam or Laos, then the command could be given for the offensive. In its position near Khe Sanh, the front could launch a counterattack against an American seaborne invasion north of the DMZ, or be the blocking force against an invasion of Laos.

The Route 9 Front would also be used to start the second wave of Phase III. Documents translated by Captain Ford indicate that Hanoi wanted to use the Route 9 Front to open a gap in the American defenses south of the DMZ so that NVA Regulars could pour into South Vietnam. An NVA official summed up the Route 9 Front’s role: ‘The tasks of the Route 9 Front were to attract and annihilate enemy forces to enable the entire South Vietnamese (VC/NLF) to launch a general offensive and uprising, and when conditions permitted, to breach a section of the enemy defensive line, thus paving the way for us to advance south.’

The Route 9 Front would first play the role of tester and then convert to its role as part of the second wave. If the breakthrough occurred at Con Thien, Gio Linh or Quang Tri city, or even at Khe Sanh during the Tet Offensive, the front would advance through the gap. Thus the Route 9 Front was not created to capture Khe Sanh, nor did Khe Sanh figure into the plans as a diversion or as the climactic battle of the war. Those who believed the front was a diversion made the mistake of linking together the border attacks with Giap’s last assault on Khe Sanh in January 1968. Some also misunderstood Westmoreland’s movement and placement of his forces into I Corps. They saw it as positioning for Khe Sanh and as the result of his fear of losing the two provinces.

After the border battles of October and November 1967, Giap returned his attention to the area along the DMZ, and the two northern provinces were placed under Giap’s command. Because it was the closest base to Laos and North Vietnam, Khe Sanh became the location of Giap’s final test. Giap launched an assault on January 21, 1968, just 10 days before Tet. When Westmoreland responded the same way he had during the past two years–with more firepower and the placement of more units inside I Corps–Giap knew the United States would not counterattack outside the South Vietnamese borders. The next day, the final order to begin Phase II was issued. The primary purpose for Khe Sanh had been fulfilled, in Giap’s opinion. The January 21 assault gave Giap the flexibility to use his forces for the most beneficial outcome. After the attack, Westmoreland still believed the primary target to be I Corps. In a cable to Joint Chiefs of Staff Chairman General Earl Wheeler, dated January 22, Westmoreland said that the enemy might launch a multibattalion attack against Hue and Quang Tri, the capitals of the two northern provinces.

Even though the first contact between the Marines and the NVA divisions occurred on December 21, 1967, on December 27 Westmoreland ordered the Marines at Khe Sanh to scout assault routes into Laos, and he cabled Washington with a detailed proposal for a strike across the border. As late as December Westmoreland had two objectives: enter Laos and defend I Corps. He did not seem to believe that the appearance of NVA forces around Khe Sanh was a diversion by Giap. In an article he wrote for the February 1993 issue of Vietnam, Westmoreland explained, ‘The most logical course for the enemy, it seemed to me, was to make a strong effort to overrun the two northern provinces while at the same time launching lesser attacks throughout the country.’ Intelligence information and MACV staff agreed with Westmoreland’s perception.

A captured document from the command authority of the enemy’s Military Region 4 indicated an objective to establish a front line that extended from Khe Sanh to Hai Van Pass with the potential to capture Quang Tri province. General Davidson briefed Westmoreland on November 29 and concluded after war games and analysis of available intelligence that Giap’s best chance of success was to pin allied forces in the Highlands and make his main effort in the two northern provinces with four or five divisions. By that time Westmoreland had begun to link Khe Sanh with an offensive to capture the two provinces. In 1969 Westmoreland reflected on how he thought Giap would have used Khe Sanh to capture part of South Vietnam: ‘In conjunction with the General Uprising, the enemy apparently expected to seize by military action large portions of the northern two provinces lying just south of the Demilitarized Zone and there set up a ‘liberated government.’ The virtually unpopulated Khe Sanh Plateau, which lay astride the enemy’s principal avenue of approach from his large base areas in Laos, was obviously an initial objective of the North Vietnamese Army. Its seizure would have created a serious threat to our forces defending the northern area and would have cleared the way for the enemy’s advance to Quang Tri City the heavily populated coastal region.’

By the beginning of January 1968, Westmoreland had completed a complex shift of American and South Korean units, code-named ‘Checkers,’ from around Saigon and out of the Highlands into I Corps. The day after the first assault on Khe Sanh, he moved the 1st Cavalry and 101st divisions into I Corps. The two divisions were placed 10 miles northwest of Hue–not near Khe Sanh. In his 1993 article, Westmoreland wrote that reconnaissance revealed the enemy was building a road in the A Shau Valley in the direction of Hue. The placement of the U.S. divisions provided Westmoreland with several options. He could move them to plug a breakthrough anywhere along the DMZ, counterattack any city captured by the VC, block a surprise flanking attack out of the A Shau Valley, relieve a surrounded base or lead the long-hoped-for assault into Laos. MACV viewed I Corps as the crucial zone in Vietnam that could determine the course of the war for the next several years. And Westmoreland thought Khe Sanh was the most crucial battlefield in the zone. But in January, Westmoreland received another rejection for the Laotian incursion. Then, on January 2, five high-ranking NVA officers were killed outside the Khe Sanh combat base. Westmoreland now anticipated an attack on Khe Sanh. He again changed the base’s purpose–this time it would be made into a killing zone.

‘If the North Vietnamese wanted to belly up to American defenses the way they had at Dak To and Loc Ninh and although a threat to the Marines,’ General Pearson said, ‘it was an undeniable opportunity to direct concentrated air strikes against a known enemy position on a sustained basis.’ Westmoreland agreed. The year before he had crushed one division at Con Thien, where he learned that massed firepower is sometimes in itself sufficient to force a besieging enemy to desist. As Neil Sheehan wrote in A Bright Shining Lie, Hanoi’s ambition was Westmoreland’s opportunity to bury Hanoi’s divisions under a cascade of bombs.

Westmoreland had studied the First Indochina War, and he even met privately with French General Paul Vanuxem, a veteran of that earlier war, who supported Westmoreland’s view of Giap and advised him to hold on to Khe Sanh. Westmoreland believed that the Communists would seek negotiations after seizing Quang Tri and Thua Thien, but he thought they would also seek a major victory before the talks. The mistake in his reasoning was that the French and Viet Minh had agreed to talk before the battle started, but the Americans and Hanoi had not even agreed to begin talks.

Westmoreland’s belief that a major attack was imminent was supported when at the Battle of Dak To the Americans captured a Communist front command directive that provided roles and missions for the winter-spring offensive, specifically for NVA troops to ‘annihilate a major U.S. element.’ However, the captured document did not identify where. In November Westmoreland decided that if he were Giap, the offensive would be directed at Khe Sanh. In early January, Westmoreland prepared to meet the anticipated assault head-on with firepower. By January 5, he had conceived and planned Operation Niagara, the Boeing B-52 bombing of the area around the Khe Sanh combat base (see this issue’s Web site article, at, beginning November 15, 1999). But Westmoreland still planned to defend I Corps (by moving the 1st Cavalry there) and in the future drive into Laos.

Simultaneously, Giap began to sense that Khe Sanh seemed to be worth much more to the Americans than just its normal military value. An increase in the number of press stories focusing on Khe Sanh, which always seemed to be monitored by the Communists, indicated that President Johnson was worried Khe Sanh would become another Dien Bien Phu. In fact, in December Walt Rostow briefed the president on that very idea. Although Giap planned to use Khe Sanh as the final test, he recognized another possibility–maybe Khe Sanh could divert Washington’s attention, and perhaps Johnson’s fear might force Westmoreland to divert his attention. Giap went so far as to use Wilford Burchett, an Australian Communist reporter, to plant a story that the general was personally in command at Khe Sanh. Giap did play the diversion card, but the plan was not conceived until December and not implemented until January.

Many Americans overreacted, thinking Khe Sanh would be another Dien Bien Phu. But the Khe Sanh siege was different. According to Peter Braestrup in his book The Big Story, published in the 1980s, ‘The major differences between Khe Sanh and Dien Bien Phu [that] were observable in Vietnam during the siege concerned logistics, material, distance to friendly forces, besiegers’ efforts to take ground, and the relative firepower of both sides.’ The main reasons Khe Sanh never became another Dien Bien Phu were firepower, air supply and Giap’s option play.

During the the Battle of Dien Bien Phu, the French had mustered 100 aircraft, while at Khe Sanh the Americans had more than 2,000 bombers and 3,000 helicopters on call. The French had launched an average of 189 sorties a day, dropping 175 tons of bombs, whereas U.S. air power averaged 320 sorties delivering 1,282 tons. The B-52s of Westmoreland’s Operation Niagara unleashed 59,542 tons of ordnance. In 10 weeks the Air Force, Navy and Marines dropped 103,500 tons in a five-square-mile area around Khe Sanh. Westmoreland called it ‘one of the heaviest and most concentrated displays of firepower in the history of war.’

Because of air supply by the Military Airlift Command, Khe Sanh could be considered not a siege like Dien Bien Phu but a battle in which the Marines were at the most forward salient in the front lines. In 1982, Khe Sanh veteran Captain William Dabney said: ‘In my understanding of the term, we were certainly not cut off from the outside world. We could reinforce, we could withdraw, we could resupply and we could support. We were in a position where land reinforcements would have been quite difficult, but in all senses we were not besieged as such.’ The French dropped only 100 tons of supplies on average each day, but the Americans dropped 1,200 tons a day at the height of battle throughout all of February.

After January 31, as the Tet Offensive got underway, Giap continued his operations at Khe Sanh. Many historians believe its main purpose was as a diversion, citing that Giap never intended to seize the base because he never seriously attacked the base. According to Giap, ‘We strictly followed this fundamental principle of the conduct of a revolutionary war: strike to win, strike only when success is certain; if it is not, then don’t strike.’ On January 22, the day after the first assault on Khe Sanh, a defector, Private Lai Van Minh, after surrendering to Marines at Khe Sanh, declared that his political officer had told the men that if the initial attack on Khe Sanh failed, North Vietnamese forces would pull back into Laos and then return to attack again around February 3. This did occur, but two more assaults failed. Between February 7 and 10, three regiments of the Route 9 Front slipped away and ended up fighting the 1st Cavalry outside Hue.

General Giap continued the assaults not because Khe Sanh was a diversion but because Phase II had stalled, except at Hue, and he hoped to jump-start it again. He also realized that with the firepower the Americans had assembled in defense of Khe Sanh he could not take the base. Thus he reverted back to his offensive doctrine and hoped to keep Phase II afloat. When it became apparent that Phase II was unsuccessful, he canceled the second wave of the phase. Westmoreland carried out the relief of Khe Sanh, called Operation Pegasus, but only after I Corps was stabilized and secured. In fact, Westmoreland also reverted to Khe Sanh’s pre-Tet purpose as a jump-off point for the Laos invasion, which as late as March 10 he believed would be approved.

War, as Karl von Clausewitz pointed out in 1832, is waged ‘against an animate object that reacts.’ A war is not a perfect series of cause-and-effect events. Nor is an offensive or battle a perfectly followed script. Opposing commanders are constantly changing, developing and reacting to each other. This state of flux makes the course of a war, an offensive or a battle dynamic and unpredictable. This happened in the Vietnam War between Giap and Westmoreland. Khe Sanh became the crossroads of the two generals. In a 1988 interview, Laura Palmer asked Westmoreland if he could sit down with any of the NVA commanders, who would it be and what would he ask them. The general replied, ‘Giap’ and said he wanted to ask him why he launched the Tet Offensive, and how he knew that the Americans were not going to cross the Laotian or Cambodian borders. But those questions now have been answered.

This article was written by James I. Marino and and was originally published in the December 1999 issue of Vietnam magazine.

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