Reconsidering the 1968 Tet Offensive

Abstract

While a tactical defeat for the Communists, the Tet Offensive is acknowledged as the turning point of the Vietnam War that ultimately led to the fall of South Vietnam. Forty years on, this article examines why the Tet Offensive was such an important event, and reassesses its legacy, especially as it relates to the use of military force today.

January marked the fortieth anniversary of the 1968 Tet Offensive. This event proved to be the turning point of the Vietnam War and its effects were far-reaching. Despite the fact that the Communists were soundly defeated at the tactical level, the Tet Offensive resulted in a great psychological victory for the other side at the strategic level that set into motion the events that would lead to Richard Nixon’s election, the long and bloody US withdrawal from South-East Asia, and ultimately to the fall of South Vietnam.

To understand how and why this happened, one must first go back to the previous year. After more than two years of bitter fighting, many in the United States believed that the war had degenerated into a bloody stalemate. General William Westmoreland, senior US commander in Vietnam, did not see it that way and by his primary metric—the body count—the US and allied forces were making significant headway against the enemy on the battlefield. Based on Westmoreland’s optimistic assessments and beset by the growing anti-war movement at home, President Lyndon Johnson initiated what we would now call an information campaign to convince the population of the United States that the war was being won and that administration policies were succeeding. As part of this effort, he brought Westmoreland home in mid November 1967 to make the administration’s case. In a number of venues, he did just that; upon his arrival at Andrews Air Force Base, Westmoreland told waiting reporters that he was ‘very, very encouraged’ by recent events. Two days later, at a press conference, he said that he thought American troops could begin to withdraw ‘within two years or less’.¹ During an address at the National Press Club, he claimed that ‘we have reached an important point where the end begins to come into view’.² Westmoreland later said that he was concerned at the time about fulfilling the public relations task, but he nevertheless gave a positive, up-beat account of how things were going in the war, clearly believing that a corner had been turned.

Meanwhile, in Vietnam, even as Westmoreland spoke, the Communists were finalising preparations for a country-wide offensive designed to break the stalemate and ‘liberate’ South Vietnam. The decision to launch the general offensive was the result of years of internal struggle and heated debates over both policy and military strategy within the Communist camp. These struggles were principally over the timing involved in shifting from a protracted war toward a more decisive approach to winning the war, but, in the end, the more cautious proponents of protracted war were defeated by those who advocated a nationwide general offensive.

With the new offensive the Communists hoped to ‘to gain a decisive victory.’ The plan for the offensive, dubbed Tong Cong Kich-Tong Khoi Nghia, was designed to ignite a general uprising among the people of South Vietnam, shatter the South Vietnamese armed forces, topple the Saigon regime, and convince the United States that the war was unwinnable. At the very least, the decision makers in Hanoi hoped to position themselves for any follow-on negotiations, which conformed to their ‘fighting while negotiating’ strategy.

The planning for the offensive began in the summer months of 1967; the target date for launching the offensive was the beginning of Tet, the lunar New Year. During the second half of 1967, in what we would today call shaping operations, the Communists launched a number of attacks to draw US and allied attention away from the population centres, which would be the ultimate objectives for the offensive in early 1968. Communist attacks on US Marine positions in the hills around Khe Sanh, near the Laotian border in I Corps Tactical Zone (I CTZ) and the siege of the Marine base at Con Thien just south of the Demilitarized Zone, also in I CTZ, coupled with additional enemy attacks at Loc Ninh, Song Be, and Dak To served to divert allied forces to the remote border areas. While these battles raged, additional Communist forces made preparations for the coming offensive and began infiltrating into the urban areas.

US military intelligence analysts knew that the Communists were planning some kind of large-scale attack, but did not believe it would come during Tet or that it would be nationwide. Still, there were many indicators that the enemy was planning to make a major shift in its strategy to win the war. In late November, the Central Intelligence Agency (CIA) station in Saigon compiled all the various intelligence indicators and published a report called ‘The Big Gamble’.³ This was not really a formal intelligence estimate or even a prediction, but rather ‘a collection of scraps’ that concluded that the Communists were preparing to escalate the fighting. This report also put enemy strength at a much higher level than previously supposed. Military intelligence analysts at Military Assistance Command Vietnam (MACV) strongly disagreed with the CIA’s estimate, because at the time, the command was changing the way it was accounting for the enemy and was reducing its estimate of enemy capabilities.

Nevertheless, as more intelligence poured in, Westmoreland and his staff came to the conclusion that a major enemy effort was probable. All the signs pointed to a new offensive. Still, most of the increased enemy activity had been along the DMZ and in the remote border areas. In late December 1967, additional signals intelligence revealed that there was a significant enemy build-up in the Khe Sanh area. Deciding that this was where the main enemy threat lay, General Westmoreland focused much of his attention on the northernmost provinces.

Concerned with the situation developing at Khe Sanh and a new round of intelligence indicators, Westmoreland requested that the South Vietnamese cancel the coming countrywide Tet ceasefire. On 8 January 1968, the chief of the South Vietnamese Joint General Staff (JGS), General Cao Van Vien, told Westmoreland that he would try to limit the truce to twenty-four hours. However, South Vietnamese President Nguyen Van Thieu argued that to cancel the forty-eight-hour truce would adversely affect the morale of his troops and the South Vietnamese people. Nevertheless, he agreed to limit the ceasefire to thirty-six hours, beginning on the evening of 29 January. Traditionally, South Vietnamese soldiers returned to their homes for the Tet holiday and this fact would play a major role in the desperate fighting to come.

On 21 January, the North Vietnamese began the first large-scale shelling of the Marine base at Khe Sanh, which was followed by renewed sharp fights between the enemy troops and the Marines in the hills surrounding the base. Westmoreland was sure that this was the opening of the long anticipated general offensive. The fact that the Khe Sanh situation looked similar to that which the French had faced when they were decisively defeated at Dien Bien Phu in 1954 only added increased urgency to the unfolding events there.

Accordingly, Westmoreland ordered the commencement of Operation NIAGARA II, a massive bombing campaign focused on suspected enemy positions around Khe Sanh. He also ordered the 1st Cavalry Division from the Central Highlands to Phu Bai just south of Hue. Additionally, he sent one brigade of the 101st Airborne Division to I Corps to strengthen the defences of the two northernmost provinces. By the end of January, more than half of all US combat manoeuvre battalions were located in the I Corps area, ready to meet any new threat.

Essentially, the Allied forces were preparing for the wrong battle. The Tet Offensive represented, in the words of National Security Council staff member William Jorden, writing in a February 1968 cable to presidential advisor Walt Rostow, ‘the worst intelligence failure of the war’.⁴ Many historians and other observers have endeavoured to understand how the Communists were able to achieve such a stunning level of surprise. There are a number of possible explanations. First, allied estimates of enemy strengths and intentions were flawed. Part of the problem was that MACV had changed the way that it computed enemy order of battle and downgraded the intelligence estimates about Viet Cong (VC)/ People’s Army of Vietnam (PAVN) strength, no longer counting the National Liberation Front local militias in the enemy order of battle. CIA analyst Sam Adams later charged that MACV actually falsified intelligence reports to show progress in the war. Whether this accusation was true is subject to debate, but it is a fact that MACV revised enemy strength downward from almost 300 000 to 235 000 in December 1967. US military intelligence analysts apparently believed their own revised estimates and largely disregarded the mounting evidence that the Communists not only retained a significant combat capability but also planned to use that capability in a dramatic fashion.

Given those grossly flawed intelligence estimates, senior allied military leaders and most of their intelligence analysts greatly underestimated the capabilities of the enemy and dismissed new intelligence indicators because they too greatly contradicted prevailing assumptions about the enemy’s strength and capabilities. It was thought that enemy capabilities were insufficient to support a nationwide campaign.

One analyst later admitted that he and his colleagues had become ‘mesmerized by statistics of known doubtful validity ... choosing to place our faith in the ones that showed progress’.⁵ These entrenched beliefs about the enemy served as blinders to the facts, colouring the perceptions of senior allied commanders and intelligence officers when they were presented with intelligence that differed so drastically with their preconceived notions.

Another problem that had an impact on the intelligence failures in Tet deals with what is known today as ‘fusion’. Given the large number of indicators drawn from a number of sources operating around South Vietnam, the data collected was difficult to assemble into a complete and cohesive picture of what the Communists were doing. The analysts often failed to integrate cumulative information, even though they were charged with the production of estimates that should have facilitated the combination of different indicators into an overall analysis. Part of this problem can be traced to the lack of coordination between allied intelligence agencies. Most of these organisations operated independently and rarely shared their information with each other. This lack of coordination and failure to share information impeded the synthesis of all the intelligence that was available and precluded the fusion necessary to predict enemy intentions and prevent the surprise of the enemy offensive when it came.

Even if the allied intelligence apparatus had been better at fusion, it would still have had to deal with widely conflicting reports that further clouded the issue. While the aforementioned intelligence indicated that a general offensive was in the offing, there were a number of other intelligence reports indicating that the enemy was facing extreme hardships in the field and that his morale had declined markedly. It was difficult to determine which reports to believe. Additionally, some indicators that should have caused alarm among intelligence analysts got lost in the noise of developments related to more obvious and more widely expected adversary threats. Faced with evidence of increasing enemy activity near urban areas and along the borders of the country, the allies were forced to decide where, when, and how the main blow would fall. They failed in this effort, choosing to focus on the increasing intensity of activity and engagements at Khe Sanh and in the other remote areas.

Westmoreland and his analysts failed to foresee a countrywide offensive, thinking that there would be perhaps a ‘show of force’, but otherwise the enemy’s main effort would be directed at the northern provinces. When indications that North Vietnamese Army units were massing near Khe Sanh were confirmed by the attack on the Marine base on 21 January, this fit well with what Westmoreland and his analysts already expected. Thus, they evaluated the intelligence in light of what they already believed, focusing on Khe Sanh and discounting most of the rest of the indicators that did not ‘fit’ with their preconceived notions about enemy capabilities and intentions.

For these reasons, the Tet Offensive achieved almost total surprise. This is true even though a number of attacks were launched prematurely against five provincial capitals in II Corps Tactical Zone and Da Nang in I Corps Tactical Zone in the early morning hours of 30 January. These early attacks, now credited to enemy coordination problems, provided at least some warning, but many in Saigon continued to believe that these attacks were only meant to divert attention away from Khe Sanh. The next night, the situation became clearer when the bulk of the Communist forces struck with a fury that was breathtaking in both its scope and suddenness. More than 84 000 North Vietnamese and Viet Cong soldiers launched coordinated, nearly simultaneous attacks against major cities, towns, and military installations that ranged from the Demilitarized Zone in the north far to the Ca Mau Peninsula on the southernmost-tip of South Vietnam. North Vietnamese and Viet Cong troops attacked thirty-nine of South Vietnam’s forty-four provincial capitals, five of the six largest cities including Saigon, seventy-one of 242 district capitals, some fifty hamlets, virtually every allied airfield, and many other key military targets, including all four military region headquarters. A US general remarked that the situation map depicting enemy attacks ‘lit up like a pinball machine’. In Saigon, the Communists attacked every major installation, including Tan Son Nhut Air Base, the presidential palace, and the headquarters of South Vietnam’s general staff. In one of the most spectacular attacks of the entire offensive, nineteen Viet Cong sappers conducted a daring raid on the new US Embassy, which had just been occupied in September. Far to the north, 7500 NLF and North Vietnamese overran and occupied Hue, the ancient imperial capital that had been the home of the emperors of the Kingdom of Annam.

The spectacular attacks, unprecedented in their magnitude and ferocity, were completely unexpected, because they contradicted both the key assumptions made by the military and the optimistic reports that came out of the Johnson administration in the closing months of 1967. Television news anchor Walter Cronkite perhaps said it best when he asked, no doubt voicing the sentiment of many in the United States, ‘What the hell is going on: I thought we were winning the war’.⁶

In truth, the Tet Offensive turned out to be a disaster for the Communists, at least at the tactical level. While the North Vietnamese and Viet Cong enjoyed initial successes with their surprise attacks, allied forces recovered their balance and responded quickly, containing and driving back the attackers in most areas. The first surge of the offensive was over by the second week of February and most of the battles were over in a few days, but heavy fighting continued for awhile in Kontum and Ban Me Thuot in the Central Highlands, Can Tho and Ben Tre in the Mekong Delta, and the Marines were still under siege at Khe Sanh. Protracted battles would also rage for several weeks in Saigon and Hue, but in the end, allied forces used superior mobility and firepower to rout the Communists, who failed to hold any of their military objectives. As for the much anticipated general uprising of the South Vietnamese people, it never materialised. The Communists had planned the offensive, counting on the general uprising to reinforce their attacks; when it didn’t happen, they lost the initiative and were forced to withdraw or die in the face of the allied response.

During the bitter fighting, the Communists sustained staggering casualties. Conservative estimates put Communist losses in 1968 at around 45 000 killed with an additional 7000 captured. The estimate of enemy killed has been disputed, but it is clear that their losses were huge and the numbers continued to grow as subsequent fighting extended into the Autumn months. By September, when the offensive had run its course, the Viet Cong, who bore the brunt of much of the heaviest fighting in the cities, had been dealt a significant blow from which they never completely recovered; the major fighting for the rest of the war was done by the North Vietnamese Army.

The offensive resulted in an overwhelming defeat of the Communist forces at the tactical level, but the fact that the enemy had pulled off such a widespread offensive and caught the allies by surprise ultimately contributed to victory for the Communists at the strategic level. Although the US and allied casualties were much lower than those of the enemy, they were still very high; on 18 February 1968, Military Assistance Command Vietnam posted the highest US casualty figure for a single week during the entire war—543 killed and over 2500 wounded. Altogether for the offensive, US, Australian, New Zealand, South Korean and Thai forces suffered over 1500 killed and some 7000 wounded in action. The South Vietnamese had about 2800 killed and over 8000 wounded. These casualty figures combined with the sheer scope and ferocity of the offensive and the vivid images of the savage fighting on the nightly television news stunned the people of the United States, who were astonished that the enemy was capable of such an effort (the charges about biased reporting and its impact on public perceptions will not be addressed here). They were unprepared for the intense and disturbing scenes they saw on television because Westmoreland and the administration had told them that the United States was winning and that the enemy was on its last legs.

Although there was a brief upturn in the support for the administration in the days immediately following the launching of the offensive, this was short-lived and subsequently the president’s approval rating plummeted. Having accepted the optimistic reports of military and government officials in late 1967, it now appeared to many in the United States that there was no end to the war in sight. The Tet Offensive severely strained the administration’s credibility with the US population and increased public discontent with the war.

The Tet Offensive also had a major impact on the White House. It profoundly shook the confidence of the president and his advisors. Despite Westmoreland’s claims that the Tet Offensive had been a great victory for the allied forces, Johnson, like the majority of the United States, was stunned by the ability of the Communists to launch such widespread attacks. One advisor later commented that an ‘air of gloom’ hung over the White House. When Westmoreland, urged on by General Earle Wheeler, Chairman of the Joint Chiefs, asked for an additional 206 000 troops to ‘take advantage of the situation’; the president balked and ordered a detailed review of US policy in Vietnam by Clark Clifford, who was to replace Robert McNamara as Secretary of Defense. According to the Pentagon Papers, ‘A fork in the road had been reached and the alternatives stood out in stark reality’.⁷ The Tet Offensive fractured the administration’s consensus on the conduct of the war and Clifford’s reassessment permitted the airing of those alternatives. The civilians in the Pentagon recommended that allied efforts focus on population security and that the South Vietnamese be forced to assume more responsibility for the fighting while the United States pursued a negotiated settlement. The Joint Chiefs naturally took exception to this approach and recommended that Westmoreland be given the troop increase he had requested and be permitted to pursue enemy forces into Laos and Cambodia. Completing his study, Clifford recommended that Johnson reject the military’s request and shift effort toward de-escalation.⁸ Although publicly optimistic, Johnson had concluded that the current course in Vietnam was not working. He was further convinced that a change in policy was needed after the ‘Wise Men’, a group of senior statesmen whom he had earlier turned to for counsel and who had previously been very supportive of administration Vietnam policies, advised that de-escalation should begin immediately.

With these debates ongoing in the White House, Congress got into the act on 11 March when the Senate Foreign Relations Committee began hearings on the war. The House of Representatives initiated their own review of Vietnam policy the following week.

Meanwhile, public opinion polls revealed the continuing downward trend in the president’s approval rating and his handling of the war. This situation manifested itself in the Democratic Party presidential primary in New Hampshire, where the president barely defeated challenger Senator Eugene McCarthy, a situation which convinced Robert Kennedy to enter the presidential race as an antiwar candidate.

Beset politically by challengers from within his own party and seemingly still in shock from the spectacular Tet attacks, Johnson went on national television on the evening of 31 March 1968, and announced a partial suspension of the bombing campaign against North Vietnam and called for negotiations. He then stunned the television audience by announcing that he would not run for re-election; the Tet Offensive had claimed its final victim. The following November, Richard Nixon won the presidential election and began the long US withdrawal from Vietnam.

Historians are reluctant to draw ‘lessons learned’ from historical events. History never repeats itself; there are just too many variables involved in situations that are separated in time. This is particularly true when comparing the wars in Vietnam and Iraq. There are more differences than similarities between the two wars and because they differ in so many significant ways, attempting to apply any lessons from Vietnam to the situation in Iraq is fraught with peril. That being said, however, there are some broad, general lessons learned in Vietnam that can inform US actions, not only in Iraq, but in any contemporary situation in which the government of the United States, or any national government for that matter, contemplates intervention and the use of military force; this is particularly true with regard to the 1968 Tet Offensive.

There are two very important and closely related lessons that can be gleaned from the Tet Offensive. The first has to do with the importance of objectivity in intelligence. Westmoreland and other senior officials were blinded to the indications that a countrywide offensive was imminent because they did not conform to their own preconceived notions about the enemy capabilities and allied progress in the war. Even when the offensive was launched, the initial reaction at Westmoreland’s headquarters was to place the attacks within the framework of those notions, seeing them as diversionary actions meant to focus attention away from what was seen as the main objective at Khe Sanh. Military planners must remain open-minded with regard to enemy capabilities and intentions, particularly when indicators run in the face of previous assessments. In the case of the Tet Offensive, intelligence became an extension of Westmoreland’s optimism and not an accurate reflection of the enemy’s capabilities. This gross failure of intelligence set the stage for the spectacular impact of the Tet attacks.

The second lesson drawn from the Tet Offensive is closely intertwined with the intelligence issue. Senior military commanders and policy makers must recognise the importance of building realistic expectations while resisting the inclination to put the best face on the military situation for political or public relations reasons. Johnson and Westmoreland built a set of, as it turned out, false expectations about the situation in Vietnam in order to win support for the administration’s handling of the war and dampen the anti-war sentiment. These expectations, based on a severely flawed (or manipulated if one believes Sam Adams)⁹ intelligence picture, played a major role in the impact of the Tet Offensive. The images and news stories of the bitter fighting seemed to put the lie to the administration’s claims of progress in the war and stretched the credibility gap to the breaking point. The tactical victory quickly became a strategic defeat for the United States and led to the virtual abdication of the president. North Vietnamese General Tran Do perhaps said it best when he acknowledged that the offensive failed to achieve its major tactical objectives, but said, ‘As for making an impact in the United States, it had not been our intention—but it turned out to be a fortunate result’.¹⁰ That result occurred because Westmoreland and the Johnson Administration let political considerations overwhelm an objective appraisal of the military situation. In doing so, they used flawed intelligence to portray an image of enemy capabilities in order to garner public support. When this was revealed by the vivid images of the Tet fighting, the resulting loss of credibility for the president and the military high command in Saigon was devastating both to the Johnson Administration and the allied war effort.

These lessons are just as applicable today. Senior US commanders in Iraq appear to have heeded them. They have been very measured in their discussion of the successes of the surge and progress in the war. They have studiously avoided building any undue expectations and have repeatedly said that there will be tough times ahead. Their avoidance of the same kind of public relations ploy that came back to haunt Westmoreland and Johnson will be instrumental in helping to contain the impact of any future Tet-like offensive by the insurgents. This is particularly important in a US election year, when the political future of the US military commitment in Iraq hangs in the balance.

The Tet Offensive and its aftermath significantly altered the nature of the war in Vietnam. The resounding tactical victory was seen as a defeat in the United States. It proved to many in the United States that the war was unwinnable, effectively toppled a president, convinced the new president to ‘Vietnamize’ the war, and paved the way for the ultimate triumph of the Communist forces in 1975. In assessing the Tet Offensive and the lessons to be learned from it, perhaps journalist Don Oberdorfer said it best when he wrote, ‘The North Vietnamese and Viet Cong lost a battle. The United States Government lost something even more important — the confidence of its people at home’.¹¹ That’s a lesson that is just as critical today as it was forty years ago.

Disclaimer: The views expressed are those of the author and do not reflect the official policy or position of the US Army, the US Department of Defense or the US Government.

Endnotes

1     Quoted in Don Oberdorfer, Tet! The Turning Point in the Vietnam War, Johns Hopkins University Press, Baltimore, 2001, p. 104.

2     Quoted in Spencer Tucker, Vietnam, UCL Press, London, 1999, p. 136.

3     Oberdorfer, Tet!, p. 120; William C Gibbons, The U.S. Government and the Vietnam War, Vol. 4, Princeton University Press, Princeton, 1995, pp. 942-43.

4     Quoted in David F Schmitz, The Tet Offensive: Politics, War, and Public Opinion, Rowman & Littlefield Publishers, Lanham, 2005, p. 84.

5     -- The Pentagon Papers: The Defense Department History of United States Decisionmaking on Vietnam, Senator Gravel Edition, Vol. IV, Beacon Press, Boston, 1971, pp. 556-58.

6     Quoted in Robert D Schulzinger, A Time for War: The United States and Vietnam, 1941-1975, Oxford University Press, New York, 1997, p. 262.

7   -- The Pentagon Papers, Vol. IV, p. 549.

8     Stanley Karnow, Vietnam: A History, Second Edition, Penguin Books, New York, 1997, pp. 567-70.

9     Sam Adams, a CIA analyst, charged that MACV had falsified enemy strength figures in order to show progress in the war. These charges led to a CBS News TV documentary entitled ‘The Uncounted Enemy: A Vietnam Deception’. General Westmoreland subsequently sued the television network for $120 million for defaming his honour, naming Adams as one of the co-defendants. Westmoreland withdrew his suit before it went to trial. See Sam Adams, War of Numbers: An Intelligence Memoir, Steerforth, South Royalton, 1994 and Don Kowet, A Matter of Honor, Macmillan, New York, 1984.

10    Quoted in Karnow, Vietnam: A History, p. 547.

11    Oberdorfer, Tet!, p. 329.