Leading up to the Tet Offensive were years of marked political instability and a series of coups after the 1963 South Vietnamese coup. In 1966, the leadership in South Vietnam, represented by the Head of State Nguyễn Văn Thiệu and Prime Minister Nguyễn Cao Kỳ were persuaded to commit to democratic reforms in an effort to stabilize the political situation at a conference in Honolulu. Prior to 1967, the South Vietnamese constituent assembly was in the process of drafting a new constitution and eventual elections.^[23] The political situation in South Vietnam, after the 1967 South Vietnamese presidential election, looked increasingly stable. Rivalries between South Vietnam's generals were becoming less chaotic, and Thiệu and Kỳ formed a joint ticket for the election. Despite efforts by North Vietnam to disrupt elections, higher than usual turnouts saw a political turning point towards a more democratic structure and ushered in a period of political stability after a series of coups had characterized the preceding years.^[24]

Protests, campaigning and the atmosphere of elections were interpreted by the Politburo of the Communist Party of Vietnam and Lê Duẩn as signs that the population would embrace a 'general uprising' against the government of South Vietnam. The Politburo sought to exploit perceived instability and maintain political weakness in South Vietnam.^[25]

During late 1967, the question whether the U.S. strategy of attrition was working in South Vietnam weighed heavily on the minds of the American public and the administration of President Lyndon B. Johnson. General William C. Westmoreland, the commander of the Military Assistance Command, Vietnam (MACV), believed that if a "crossover point" could be reached by which the number of communist troops killed or captured during military operations exceeded those recruited or replaced, the Americans would win the war. There was a discrepancy, however, between the order of battle estimates of the MACV and the Central Intelligence Agency (CIA) concerning the strength of VC guerrilla forces within South Vietnam.^{[16]: 22–23} In September, members of the MACV intelligence services and the CIA met to prepare a Special National Intelligence Estimate that would be used by the administration to gauge U.S. success in the conflict.

Provided with an enemy intelligence windfall accrued during Operations Cedar Falls and Junction City, the CIA members of the group believed that the number of VC guerrillas, irregulars, and cadre within the South could be as high as 430,000. The MACV Combined Intelligence Center, on the other hand, maintained that the number could be no more than 300,000.^[16]: 22 Westmoreland was deeply concerned about the possible perceptions of the American public to such an increased estimate since communist troop strength was routinely provided to reporters during press briefings.^[26] According to MACV's chief of intelligence, General Joseph A. McChristian, the new figures "would create a political bombshell", since they were positive proof that the North Vietnamese "had the capability and the will to continue a protracted war of attrition".^[16]: 22

In May, MACV attempted to obtain a compromise from the CIA by maintaining that VC militias did not constitute a fighting force but were essentially low-level fifth columnists used for information collection.^[16]: 23 With the groups deadlocked, George Carver, CIA Special Assistant for Vietnam Affairs, represented the CIA in the last stage of the negotiations. In September, Carver devised a compromise: The CIA would drop its insistence on including the irregulars in the final tally of forces and add a prose addendum to the estimate that would explain the agency's position.^[27] George Allen, Carver's deputy, laid responsibility for the agency's capitulation at the feet of Richard Helms, the director of the CIA. He believed that "it was a political problem ... [Helms] didn't want the agency ... contravening the policy interest of the administration."^{[16]: 23 [b]}

During the second half of 1967, the administration had become alarmed by criticism, both inside and outside the government, and by reports of declining public support for its Vietnam policies.^[28] According to public opinion polls, the percentage of Americans who believed that the U.S. had made a mistake by sending troops to Vietnam had risen from 25 percent in 1965 to 45 percent by December 1967.^[16]: 68 This trend was fueled not by a belief that the struggle was not worthwhile, but by mounting casualty figures, rising taxes, and the feeling that there was no end to the war in sight.^[29] A poll taken in November indicated that 55 percent wanted a tougher war policy, exemplified by the public belief that "it was an error for us to have gotten involved in Vietnam in the first place. But now that we're there, let's win—or get out."^[30] This prompted the administration to launch a so-called "success offensive", a concerted effort to alter the widespread public perception that the war had reached a stalemate and to convince the American people that the administration's policies were succeeding. Under the leadership of National Security Advisor Walt W. Rostow, the news media then was inundated by a wave of effusive optimism.

Every statistical indicator of progress, from "kill ratios" and "body counts" to village pacification, was fed to the press and to the Congress. "We are beginning to win this struggle", asserted Vice President Hubert H. Humphrey on NBC's Today show in mid-November. "We are on the offensive. The territory is being gained. We are making steady progress."^[16]: 66 At the end of November, the campaign reached its climax when Johnson summoned Westmoreland and the new U.S. Ambassador, Ellsworth Bunker, to Washington, D.C., for what was billed as a "high-level policy review". Upon their arrival, the two men bolstered the administration's claims of success. From Saigon, pacification chief Robert Komer asserted that the CORDS pacification program in the countryside was succeeding, and that sixty-eight percent of the South Vietnamese population was under the control of Saigon while only seventeen percent was under the control of the VC.^[31]: 56 General Bruce Palmer Jr., one of Westmoreland's three Field Force commanders, claimed that "the Viet Cong has been defeated" and that "He can't get food and he can't recruit. He has been forced to change his strategy from trying to control the people on the coast to try to survive in the mountains."^[31]: 58

Westmoreland was even more emphatic in his assertions. At an address at the National Press Club on 21 November, he reported that, as of the end of 1967, the communists were "unable to mount a major offensive ... I am absolutely certain that whereas in 1965 the enemy was winning, today he is certainly losing...We have reached an important point when the end begins to come into view."^[16]: 66 By the end of the year the administration's approval rating had indeed crept up by eight percent, but an early January Gallup poll indicated that forty-seven percent of the American public still disapproved of the President's handling of the war.^[16]: 69 The American public, "more confused than convinced, more doubtful than despairing ... adopted a 'wait and see' attitude."^[16]: 67 During a discussion with an interviewer from Time magazine, Westmoreland dared the communists to launch an attack: "I hope they try something because we are looking for a fight."^[32]

Planning in Hanoi for a winter-spring offensive during 1968 had begun in early 1967 and continued until early the following year. According to American sources, there has been an extreme reluctance among Vietnamese historians to discuss the decision-making process that led to the general offensive and uprising, even decades after the event.^[33] In official Vietnamese literature, the decision to launch the Tet offensive was usually presented as the result of a perceived U.S. failure to win the war quickly, the failure of the American bombing campaign against North Vietnam, and the anti-war sentiment that pervaded the population of the U.S.^[34] The decision to launch the general offensive, however, was much more complicated.

The decision signaled the end of a bitter, decade-long debate within the North Vietnamese Government between first two, and then three factions. The moderates believed that the economic viability of North Vietnam should come before support of a massive and conventional southern war and they generally followed the Soviet line of peaceful coexistence by reunifying Vietnam through political means. Heading this faction were party theorist Trường Chinh and Minister of Defense Võ Nguyên Giáp. The militant faction, on the other hand, tended to follow the foreign policy line of the People's Republic of China and called for the reunification of the nation by military means and that no negotiations should be undertaken with the Americans. This group was led by Communist Party First Secretary Lê Duẩn and Lê Đức Thọ (no relation). From the early to mid-1960s, the militants had dictated the direction of the war in South Vietnam.^[35] General Nguyễn Chí Thanh, the head of Central Office for South Vietnam (COSVN), headquarters for the South, was another prominent militant. The followers of the Chinese line centered their strategy against the U.S. and its allies on large-scale, main force actions rather than the protracted guerrilla war espoused by Mao Zedong.^[36]

By 1966–1967, however, after suffering massive casualties, stalemate on the battlefield, and destruction of the northern economy by U.S. aerial bombing, there was a dawning realization that if current trends continued, Hanoi would eventually lack the resources necessary to affect the military situation in the South.^[37] As a result, there were more strident calls by the moderates for negotiations and a revision of strategy. They felt that a return to guerrilla tactics was more appropriate since the U.S. could not be defeated conventionally. They also complained that the policy of rejecting negotiations was in error.^[38] The Americans could only be worn down in a war of wills during a period of "fighting while talking". During 1967 things had become so bad on the battlefield that Lê Duẩn ordered Thanh to incorporate aspects of protracted guerrilla warfare into his strategy.^[39]

During the same period, a counter-attack was launched by a new, third grouping (the centrists) led by President Ho Chi Minh, Lê Đức Thọ, and Foreign Minister Nguyễn Duy Trinh, who called for negotiations.^[40] From October 1966 through April 1967, a very public debate over military strategy took place in print and via radio between Thanh and his rival for military power, Giáp.^[41] Giáp had advocated a defensive, primarily guerrilla strategy against the U.S. and South Vietnam.^{[5]: 15–16 [42]} Thanh's position was that Giáp and his adherents were centered on their experiences during the First Indochina War and that they were too "conservative and captive to old methods and past experience... mechanically repeating the past."^[5]: 16

The arguments over domestic and military strategy also carried a foreign policy element, as North Vietnam, like South Vietnam, was largely dependent on outside military and economic aid. The vast majority of North Vietnam's military equipment was provided by either the Soviet Union or China. Beijing advocated that North Vietnam conduct a protracted war on the Maoist model, fearing that a conventional conflict might draw China in, as had happened in the Korean War. They also resisted the idea of negotiating with the allies. Moscow, on the other hand, advocated negotiations, but simultaneously armed Hanoi's forces to conduct a conventional war on the Soviet model. North Vietnamese foreign policy therefore consisted of maintaining a critical balance between war policy, internal and external policies, domestic adversaries, and foreign allies with "self-serving agendas."^[43]

To "break the will of their domestic opponents and reaffirm their autonomy vis-à-vis their foreign allies", hundreds of pro-Soviet, party moderates, military officers, and intelligentsia were arrested on 27 July 1967, during what came to be called the Revisionist Anti-Party Affair.^[44] All of the arrests were based on the individual's stance on the Politburo's choice of tactics and strategy for the proposed general offensive.^[45] This move cemented the position of the militants as Hanoi's strategy: the rejection of negotiations, the abandonment of protracted warfare, and the focus on the offensive in the towns and cities of South Vietnam. More arrests followed in November and December.

The operational plan for the general offensive and uprising had its origin as the "COSVN proposal" at Thanh's southern headquarters in April 1967 and had then been relayed to Hanoi the following month. Thanh was then ordered to the capital to explain his concept in person to the Military Central Commission. At a meeting in July, Thanh briefed the plan to the Politburo.^[46] On the evening of 6 July, after receiving permission to begin preparations for the offensive, Thanh attended a party and died of a heart attack after drinking too much. An alternative account is that Thanh died of injuries sustained in a U.S. bombing raid on COSVN after having been evacuated from Cambodia.^[47]

After cementing their position during the Party crackdown, the militants sped up planning for a major conventional offensive to break the military deadlock. They concluded that the Saigon government and the U.S. presence were so unpopular with the population of the South that a broad-based attack would spark a spontaneous uprising of the population, which, if the offensive was successful, would enable the North Vietnamese to sweep to a quick, decisive victory. Their basis for this conclusion included: a belief that the South Vietnamese military was no longer combat-effective; the results of the 1967 presidential election (in which the Thiệu/Kỳ ticket had only received 24 percent of the popular vote); the Buddhist crises of 1963 and 1966; well-publicized anti-war demonstrations in Saigon; and continuous criticism of the Thiệu government in the southern press.^[5]: 24 Launching such an offensive would also finally put an end to what had been described as "dovish calls for talks, criticism of military strategy, Chinese diatribes of Soviet perfidy, and Soviet pressure to negotiate—all of which needed to be silenced."^[44]

In October, the Politburo decided on the Tet holiday as the launch date and met again in December to reaffirm its decision and formalize it at the 14th Plenary session of the Party Central Committee in January 1968.^[48] The resultant Resolution 14 was a major blow to domestic opposition and "foreign obstruction". Concessions had been made to the center group, however, by agreeing that negotiations were possible, but the document essentially centered on the creation of "a spontaneous uprising in order to win a decisive victory in the shortest time possible."^[49]

Contrary to Western belief, Giáp did not plan or command the offensive himself. Thanh's original plan was elaborated on by a party committee headed by Thanh's deputy, Phạm Hùng, and then modified by Giáp.^[50] The Defense Minister may have been convinced to toe the line by the arrest and imprisonment of most of the members of his staff during the Revisionist Anti-Communist Party Affair. Although Giáp went to work "reluctantly, under duress", he may have found the task easier due to the fact that he was faced with a fait accompli.^[51] Since the Politburo had already approved the offensive, all he had to do was make it work. He combined guerrilla operations into what was basically a conventional military offensive and shifted the burden of sparking the popular uprising to the VC. If it worked, all would be well and good. If it failed, it would be a failure only for the Communist Party militants. For the moderates and centrists, it offered the prospect of negotiations and a possible end to the American bombing of the North. Only in the eyes of the militants, therefore, did the offensive become a "go for broke" effort. Others in the Politburo were willing to settle for a much less ambitious "victory".^[52]

The PAVN official history states that the objectives of the Tet offensive were to: annihilate and cause the total disintegration of the bulk of the puppet army, overthrow the "puppet" (South Vietnamese) regime at all administrative levels, and place all government power in the hands of the people. Annihilate a significant portion of the American military's troop strength and destroy a significant portion of his war equipment in order to prevent the American forces from being able to carry out their political and military missions; on the basis, crush the American will to commit aggression and force the United States to accept defeat in South Vietnam and end all hostile actions against North Vietnam. In addition, using this as the basis, they would achieve the immediate goals of the revolution, which were independence, democracy, peace, and neutrality in South Vietnam, and then move toward achieving peace and national unification.^[53]

The operation would involve a preliminary phase, during which diversionary attacks would be launched in the border areas of South Vietnam to draw American attention and forces away from the cities. The general offensive and uprising would then commence with simultaneous actions on major allied bases and most urban areas, and with particular emphasis on the cities of Saigon and Huế. Concurrently, a substantial threat would have to be made against the U.S. Khe Sanh Combat Base. The Khe Sanh actions would draw PAVN forces away from the offensive into the cities, but Giáp considered them necessary to protect his supply lines and divert American attention.^[54] Attacks on other U.S. forces were of secondary, or even tertiary importance, since Giáp considered his main objective to be weakening or destroying the South Vietnamese military and government through popular revolt.^[5]: 26 The offensive, therefore, was aimed at influencing the South Vietnamese public, not that of the U.S. There is conflicting evidence as to whether, or to what extent, the offensive was intended to influence either the March primaries or the November presidential election in the U.S.^[55]

The offensives of 1968 had three distinct phases: Phase I, scheduled to begin on 31 January (though some attacks were launched prematurely on 30 January), would be a countrywide assault on the cities, conducted primarily by VC forces. Concurrently, a propaganda offensive to induce ARVN troops to desert and the South Vietnamese population to rise up against the government would be launched. If outright victory was not achieved, the battle might still lead to the creation of a coalition government and the withdrawal of the Americans. If the general offensive failed to achieve these purposes, follow-up operations would be conducted to wear down the enemy and lead to a negotiated settlement. Phase II began on 5 May and Phase III on 17 August.^[56]

Preparations for the offensive were already underway. The logistical build-up began in mid-year, and by January 1968, 81,000 tons of supplies and 200,000 troops, including seven complete infantry regiments and 20 independent battalions made the trip south on the Ho Chi Minh trail.^[57] This logistical effort also involved re-arming the VC with new AK-47 assault rifles and B-40 rocket-propelled grenade launchers, which granted them superior firepower over the ARVN. To pave the way and to confuse the allies as to its intentions, Hanoi launched a diplomatic offensive. Foreign Minister Trinh announced on 30 December that Hanoi would rather than could open negotiations if the U.S. unconditionally ended Operation Rolling Thunder, the bombing campaign against North Vietnam.^[16]: 10 This announcement provoked a flurry of diplomatic activity (which amounted to nothing) during the last weeks of the year.

South Vietnamese and U.S. military intelligence estimated that PAVN/VC forces in South Vietnam during January 1968 totaled 323,000 men, including 130,000 PAVN regulars, 160,000 VC and members of the infrastructure, and 33,000 service and support troops. They were organized into nine divisions composed of 35 infantry and 20 artillery or anti-aircraft artillery regiments, which were, in turn, composed of 230 infantry and six sapper battalions.^[5]: 10

Signs of impending communist action were noticed among the allied intelligence collection apparatus in Saigon. During the late summer and fall of 1967 both South Vietnamese and U.S. intelligence agencies collected clues that indicated a significant shift in communist strategic planning. By mid-December, mounting evidence convinced many in Washington and Saigon that something big was underway. During the last three months of the year intelligence agencies had observed signs of a major North Vietnamese military buildup. In addition to captured documents (a copy of Resolution 13, for example, was captured by early October), observations of enemy logistical operations were also quite clear: in October, the number of trucks observed heading south through Laos on the Ho Chi Minh trail jumped from the previous monthly average of 480 to 1,116. By November this total reached 3,823 and, in December, 6,315.^[58] On 20 December, Westmoreland cabled Washington that he expected the PAVN/VC "to undertake an intensified countrywide effort, perhaps a maximum effort, over a relatively short period of time."^[16]: 11

Despite all the warning signs, however, the allies were still surprised by the scale and scope of the offensive. According to ARVN Colonel Hoang Ngoc Lung the answer lay with the allied intelligence methodology itself, which tended to estimate the enemy's probable course of action based upon their capabilities, not their intentions. Since, in the allied estimation, the communists hardly had the capability to launch such an ambitious enterprise: "There was little possibility that the enemy could initiate a general offensive, regardless of his intentions."^[5]: 39 The answer could also be partially explained by the lack of coordination and cooperation between competing intelligence branches, both South Vietnamese and American. The situation from the U.S. perspective was summed up by an MACV intelligence analyst: "If we'd gotten the whole battle plan, it wouldn't have been believed. It wouldn't have been credible to us."^[16]: 11 The Tet offensive would later be used in a textbook at West Point as an example of "an allied intelligence failure to rank with Pearl Harbor in 1941 or the Ardennes offensive in 1944." Lieutenant Colonel Dave R. Palmer: Current Readings in Military History.^[59]: 460

From early to late 1967, the U.S. command in Saigon was perplexed by a series of actions initiated by the PAVN/VC in the border regions. On 24 April a U.S. Marine Corps patrol prematurely triggered a PAVN offensive aimed at taking Khe Sanh Combat Base, the western anchor of the Marines' defensive positions in Quảng Trị Province.^[60] For 49 days during early September and lasting into October, the PAVN began shelling the U.S. Marine outpost of Con Thien, just south of the Demilitarized Zone (DMZ).^[61]: 16 The intense shelling (100–150 rounds per day) prompted Westmoreland to launch Operation Neutralize, an intense aerial bombardment campaign of 4,000 sorties into and just north of the DMZ.^[62]

On 27 October, an ARVN battalion at Sông Bé, the capital of Phước Long Province, came under attack by an entire PAVN regiment. Two days later, another PAVN regiment attacked a U.S. Special Forces border outpost at Lộc Ninh, in Bình Long Province.^[61]: 36 This attack sparked a ten-day battle that drew in elements of the U.S. 1st Infantry Division and the ARVN 18th Division and left 800 PAVN troops dead at its conclusion.^[5]: 9

The most severe of what came to be known as "the Border Battles" erupted during October and November around Dak To, another border outpost in Kon Tum Province. The clashes there between the four regiments of the PAVN 1st Division, the U.S. 4th Infantry Division, the 173rd Airborne Brigade and ARVN infantry and Airborne elements, lasted for 22 days. By the time the fighting was over, between 1,200 and 1,600 PAVN and 262 U.S. troops had been killed.^{[5]: 9 [61]: 17} MACV intelligence was confused by the possible motives of the North Vietnamese in prompting such large-scale actions in remote regions where U.S. artillery and aerial firepower could be applied indiscriminately, which meant that tactically and strategically, these operations made no sense. What the North Vietnamese had done was carry out the first stage of their plan: to fix the attention of the U.S. command on the borders and draw the bulk of U.S. forces away from the heavily populated coastal lowlands and cities.^[63]

Westmoreland was more concerned with the situation at Khe Sanh, where, on 21 January 1968, a force estimated at 20,000–40,000 PAVN troops had besieged the U.S. Marine garrison. MACV was convinced that the PAVN planned to stage an attack and overrun the base as a prelude to an all-out effort to seize the two northernmost provinces of South Vietnam.^[64] To deter any such possibility, he deployed 250,000 men, including half of MACV's U.S. maneuver battalions, to I Corps.

This course of events disturbed Lieutenant General Frederick Weyand, commander of U.S. forces in III Corps, which included the sensitive Capital Military District. Weyand, a former intelligence officer, was suspicious of the pattern of communist activities in his area of responsibility and notified Westmoreland of his concerns on 10 January. Westmoreland agreed with his estimate and ordered 15 U.S. battalions to redeploy from positions near the Cambodian border back to the outskirts of Saigon.^[16]: 8 When the offensive did begin, a total of 27 allied maneuver battalions defended the city and the surrounding area. This redeployment may have been one of the most critical tactical decisions of the war.^[65]

By the beginning of January 1968, the U.S. had deployed 331,098 Army personnel and 78,013 Marines in nine divisions, an armoured cavalry regiment, and two separate brigades to South Vietnam. They were joined there by the 1st Australian Task Force, a Royal Thai Army regiment, two Republic of Korea Army infantry divisions, and the Republic of Korea Marine Corps brigade.^[66] South Vietnamese strength totaled 350,000 regulars in the Army, Air Force, Navy and Marine Corps.^[16]: 124 They were in turn supported by the 151,000-man South Vietnamese Regional Forces and 149,000-man South Vietnamese Popular Forces, which were the equivalent of regional and local militias.^[61]: 7

In the days immediately preceding the offensive, the preparedness of allied forces was relatively relaxed. Hanoi had announced in October that it would observe a seven-day truce from 27 January to 3 February for the Tet holiday, and the South Vietnamese military made plans to allow recreational leave for approximately half of its forces. General Westmoreland, who had already cancelled the truce in I Corps, requested that South Vietnam cancel the upcoming cease-fire, but President Thiệu (who had already reduced the cease-fire to 36 hours), refused to do so, claiming that it would damage troop morale and only benefit communist propagandists.^[16]: 12

On 28 January, eleven VC cadres were captured in the city of Qui Nhơn while in possession of two pre-recorded audio tapes whose message appealed to the populace in "already occupied Saigon, Huế, and Da Nang".^[5]: 35 The following afternoon, General Cao Văn Viên, chief of the South Vietnamese Joint General Staff,^[67] ordered his four Corps' commanders to place their troops on alert. Yet, there was still a lack of a sense of urgency on the part of the allies. If Westmoreland had a grasp of the potential for danger, he did not communicate it very well to others.^[68] On the evening of 30 January, 200 U.S. officers—all of whom served on the MACV intelligence staff—attended a pool party at their quarters in Saigon. According to James Meecham, an analyst at the Combined Intelligence Center who attended the party: "I had no conception Tet was coming, absolutely zero ... Of the 200-odd officers present, not one I talked to knew Tet was coming, without exception."^[69]

Westmoreland also failed to communicate his concerns adequately to Washington. Although he had warned the President between 25 and 30 January that "widespread" communist attacks were in the offing, his admonitions had tended to be so oblique or so hedged with official optimism that even the administration was unprepared.^[70] No one—in either Washington or Vietnam—was expecting what happened.

Weyand invited CBS News Correspondent John Laurence and Washington Post reporter Don Oberdorfer to his III Corps headquarters in the week before the Tet offensive to alert them that a major enemy attack was coming "just before or just after Tet." He said the Vietnamese had too much respect for the holiday to attack during Tet itself. Weyand said he had moved 30 U.S. and South Vietnamese battalions closer to Saigon to defend the city.^[71][72]

"Crack the Sky, Shake the Earth"

Whether by accident or design, the first wave of attacks began shortly after midnight on 30 January as five provincial capitals in II Corps and Da Nang, in I Corps, were attacked.^[73] Nha Trang, headquarters of the U.S. I Field Force, was the first to be hit, followed shortly by Buôn Ma Thuột, Kon Tum, Hội An, Tuy Hòa, Da Nang, Qui Nhơn, and Pleiku. During all of these operations, the PAVN/VC followed a similar pattern: mortar or rocket attacks were closely followed by massed ground assaults conducted by battalion-strength elements of the VC, sometimes supported by PAVN regulars. These forces would join with local cadres who served as guides to lead the regulars to the most senior South Vietnamese headquarters and the radio station. The operations, however, were not well coordinated at the local level. By daylight, almost all communist forces had been driven from their objectives. General Phillip B. Davidson, the new MACV chief of intelligence, notified Westmoreland that "This is going to happen in the rest of the country tonight and tomorrow morning."^[74]: 323 All U.S. forces were placed on maximum alert and similar orders were issued to all ARVN units. The allies, however, still responded without any real sense of urgency. Orders cancelling leaves either came too late or were disregarded.^[75]

At 03:00 on 31 January PAVN/VC forces attacked Saigon, Cholon, and Gia Định in the Capital Military District; Quảng Trị (again), Huế, Quảng Tín, Tam Kỳ and Quảng Ngãi as well as U.S. bases at Phú Bài and Chu Lai in I Corps; Phan Thiết, Tuy Hòa and U.S. installations at Bong Son and An Khê in II Corps; and Cần Thơ and Vĩnh Long in IV Corps. The following day, Biên Hòa, Long Thanh, Bình Dương in III Corps and Kien Hoa, Dinh Tuong, Gò Công, Kiên Giang, Vĩnh Bình, Bến Tre, and Kien Tuong in IV Corps were assaulted. The last attack of the initial operation was launched against Bạc Liêu in IV Corps on 10 February. A total of approximately 84,000 PAVN/VC troops participated in the attacks while thousands of others stood by to act as reinforcements or as blocking forces.^[74]: 328 Palmer gave a figure of 70,000.^[76] PAVN/VC forces also mortared or rocketed every major allied airfield and attacked 64 district capitals and scores of smaller towns.

In most cases, the defense was led by the South Vietnamese. Local militia or ARVN forces, supported by the South Vietnamese National Police, usually drove the attackers out within two or three days, sometimes within hours; but heavy fighting continued several days longer in Kon Tum, Buôn Ma Thuột, Phan Thiết, Cần Thơ, and Bến Tre.^[74]: 328 The outcome in each instance was usually dictated by the ability of local commanders—some were outstanding, others were cowardly or incompetent. During this crucial crisis, however, no South Vietnamese unit broke or defected to the communists.^[74]: 332

According to Westmoreland, he responded to the news of the attacks with optimism, both in media presentations and in his reports to Washington. According to closer observers, however, the General was "stunned that the communists had been able to coordinate so many attacks in such secrecy", and he was "dispirited and deeply shaken."^[77] According to Clark Clifford, at the time of the initial attacks, the reaction of the U.S. military leadership "approached panic".^[59]: 474 Although Westmoreland's appraisal of the military situation was correct, he made himself look foolish by continuously maintaining his belief that Khe Sanh was the real objective of the North Vietnamese and that 155 attacks by 84,000 troops was a diversion (a position he maintained until at least 12 February).^{[78][59]: 476} Washington Post reporter Peter Braestrup summed up the feelings of his colleagues by asking "How could any effort against Saigon, especially downtown Saigon, be a diversion?"^[79]

Although Saigon was the focal point of the offensive, the PAVN/VC did not seek a total takeover of the city.^[80] Rather, they had six primary targets to strike in the downtown area: the headquarters of the ARVN Joint General Staff, Tan Son Nhut Air Base, the Independence Palace, the US Embassy in Saigon, the Republic of Vietnam Navy Headquarters and Radio Saigon.^[61]: 32 Elsewhere in the city or its outskirts, ten VC Local Force Battalions attacked the central police station and the Artillery Command and the Armored Command headquarters (both at Gò Vấp). The plan called for all these initial forces to capture and hold their positions for 48 hours, by which time reinforcements were to have arrived to relieve them.

The defense of the Capital Military District was primarily a South Vietnamese responsibility and it was initially defended by eight ARVN infantry battalions and the local police force. By 3 February they had been reinforced by five ARVN Ranger Battalions, five Marine Corps, and five ARVN Airborne Battalions. U.S. Army units participating in the defense included the 716th Military Police Battalion, seven infantry battalions (one mechanized), and six artillery battalions.^[81]

At the Armored Command and Artillery Command headquarters on the northern edge of the city, the PAVN planned to use captured tanks and artillery pieces, but the tanks had been moved to another base two months earlier and the breechblocks of the artillery pieces had been removed, rendering them useless.^[74]: 326

One of the most important targets, from a symbolic and propagandistic point of view, was Radio Saigon. Its troops had brought along a tape recording of Hồ Chi Minh announcing the liberation of Saigon and calling for a "General Uprising" against the Thiệu government. They seized the building, held it for six hours and, when running out of ammunition, the last eight attackers destroyed it and killed themselves using explosive charges, but they were unable to broadcast due to the cutting off of the audio lines from the main studio to the tower as soon as the station was seized.^{[61]: 32–33 [82]}

The US Embassy in Saigon, a massive six-floor building situated within a four-acre compound, had been completed only in September. At 02:45 it was attacked by a 19-man sapper team that blew a hole in the 8-foot-high (2.4 m) surrounding wall and charged through. With their officers killed in the initial attack and their attempt to gain access to the building having failed, the sappers simply occupied the chancery grounds until they were all killed or captured by U.S. reinforcements that were landed on the roof of the building six hours later. By 09:20 the embassy and grounds were secured, with the loss of five U.S. personnel.^{[61]: 34–36}

At 03:00 on 31 January, 12 VC sappers approached the Vietnamese Navy Headquarters in two civilian cars, killing two guards at a barricade at Me Linh Square and then advanced towards the base gate. The sound of gunfire alerted base sentries, who secured the gate and sounded the alarm. A .30-caliber machine gun on the second floor of the headquarters disabled both cars and killed or wounded several sappers while the Navy security force organized a counterattack. Simultaneously a U.S. Navy advisor contacted the U.S. military police who soon attacked the VC from adjoining streets, the resulting crossfire ended the attack, killing eight sappers with two captured.^[83]

Small squads of VC fanned out across the city to attack various officers and enlisted men's billets, homes of ARVN officers, and district police stations. Provided with "blacklists" of military officers and civil servants, they began to round up and execute any that could be found.^[61]: 36

On 1 February, General Nguyễn Ngọc Loan, chief of the National Police, publicly executed VC officer Nguyễn Văn Lém in front of photographer Eddie Adams and a film cameraman. That photograph, with the title Saigon Execution, won the 1969 Pulitzer Prize for Spot News Photography and is widely seen as a defining moment in the Vietnam War for its influence on U.S. public opinion, even being called "the picture that lost the war".^{[61]: 36 [84][85]}

Outside the city proper, two VC battalions attacked the U.S. logistical and headquarters complex at Long Binh Post. Biên Hòa Air Base was struck by a battalion, while the adjacent ARVN III Corps headquarters was the objective of another. Tan Son Nhut Air Base, in the northwestern part of the city, was attacked by three battalions.^{[61]: 37–39} A combat-ready battalion of ARVN paratroopers, awaiting transport to Da Nang, went instead directly into action supporting the United States Air Force's 377th Security Police Squadron and the U.S. Army's 3rd Squadron, 4th Cavalry Regiment in halting the attack.^[5]: 40 A total of 35 PAVN/VC battalions, many of whose troops were undercover cadres who had lived and worked within the capital or its environs for years, had been committed to the Saigon objectives.^[61]: 32 By dawn most of the attacks within the city center had been eliminated, but severe fighting between VC and allied forces erupted in the Chinese neighborhood of Cholon around the Phú Thọ racetrack, southwest of the city center, which was being used as a staging area and command and control center by the PAVN/VC.^[61]: 39 Bitter and destructive house-to-house fighting erupted in the area. On 4 February, the residents were ordered to leave their homes and the area was declared a free fire zone. Fighting in the city came to a close only after a fierce battle between the ARVN Rangers and PAVN forces on 7 March.^[61]: 39

On the morning of 2 March 1968, while patrolling 4 miles (6.4 km) north of Tan Son Nhut Air Base near the small village of Quoi Xuan to locate VC rocket sites, Company C, 4th Battalion, 9th Infantry Regiment walked into an ambush losing 48 killed in just eight minutes. U.S. forces claimed they killed 20 VC.^[86] Specialist Nicholas J. Cutinha would be posthumously awarded the Medal of Honor for his actions at Quoi Xuan. General Fillmore K. Mearns would describe this as "a classic example of a properly executed ambush." The following day as US troops swept the area they were engaged by VC forces in an eight-hour battle losing three dead while killing 10 VC.^[87]

While their attacks on Saigon had been quickly repulsed, in early March, more than 20 VC battalions remained near Gia Định Province, threatening Saigon. While most of these units had suffered heavy losses in the offensive, their continued presence applied pressure on Saigon and prevented the reestablishment of South Vietnamese Government control.^{[88]: 460–1} From 11 March to 7 April, Allied forces launched Operation Quyet Thang to pacify the area around Saigon. The operation was considered a success and the U.S. claimed 2,658 VC killed and 427 captured. It was followed immediately by Operation Toan Thang I (8 April – 31 May), which expanded the security operation across III Corps and resulted in a further 7,645 VC killed and 1,708 captured for South Vietnamese losses of 708 killed, U.S. losses of 564 killed and other Allied losses of 23 killed.^{[88]: 464–7 [89]}

At 03:40 on the foggy morning of 31 January, allied defensive positions north of the Hương River in the city of Huế were mortared and rocketed and then attacked by two battalions of the PAVN 6th Regiment. Their target was the ARVN 1st Division headquarters located in the Citadel,^[61]: 46 a three-square mile complex of palaces, parks, and residences,^{[61]: xxiv, 43} which were surrounded by a moat and a massive earth and masonry fortress.^[61]: 44 The undermanned ARVN defenders, led by General Ngô Quang Trưởng, managed to hold their position, but the majority of the Citadel fell to the PAVN. On the south bank of the river, the PAVN 4th Regiment attempted to seize the local MACV headquarters,^[61]: 47 but was held at bay by a makeshift force of approximately 200 Americans.^[61]: 44 The rest of the city was overrun by PAVN forces that initially totaled approximately 7,500 men.^[90] Both sides then rushed to reinforce and resupply their forces.^{[61]: 48–49} Lasting 25 days,^[61]: 54 the battle of Huế became one of the longest and bloodiest single battles of the Vietnam War.^[91]

During the first days of the North Vietnamese occupation, U.S. intelligence vastly underestimated the number of PAVN troops and little appreciated the effort that was going to be necessary to evict them. Westmoreland informed the Joint Chiefs that "the enemy has approximately three companies in the Huế Citadel and the marines have sent a battalion into the area to clear them out."^[92] A later assessment ultimately noted three Marine and 11 Vietnamese battalions engaged at least 8 PAVN/VC battalions of the PAVN 6th Regiment, not including the large number of forces outside the city.^[93]

Since there were no U.S. formations stationed in Huế, relief forces had to move up from Phu Bai Combat Base,^[61]: 48 eight kilometers to the southeast. In a misty drizzle, U.S. Marines of the 1st Marine Division and soldiers of the 1st ARVN Division and Marine Corps cleared the city street by street and house by house,^{[61]: 50–51} a deadly and destructive form of urban combat that the U.S. military had not engaged in since the Battle of Seoul during the Korean War, and for which neither side was trained.^[16]: 28 Because of poor weather conditions, logistics problems and the historical and cultural significance of the city, American forces did not immediately apply air and artillery strikes as widely as they had in other cities.^[61]: 49

VC forces around Huế included six main-force battalions, while two PAVN regiments operated in the area. As the battle unfolded three more PAVN regiments redeployed from Khe Sanh arrived as reinforcements. The North Vietnamese plan of attack on Huế involved intensive preparation and reconnaissance. Over 190 targets, including every government and military installation on both sides of the river would be hit on January 31 by a force of five thousand. Other forces would block American and ARVN reinforcement routes, mainly Highway 1. Over half of the ARVN 1st Division was on holiday leave and PAVN commanders believed the population of Huế would join the fight as a part of the General Uprising.^[94]

Outside Huế, elements of the U.S. 1st Cavalry Division and the 101st Airborne Division fought to seal PAVN access and cut off their lines of supply and reinforcement.^[61]: 53 By this point in the battle 16 to 18 PAVN battalions (8,000–11,000 men) were taking part in the fighting for the city itself or the approaches to the city.^[95] Two of the PAVN regiments had made a forced march from the vicinity of Khe Sanh to Huế to participate. During most of February, the allies gradually fought their way towards the Citadel, which was taken only after 25 days of intense struggle. The city was not declared recaptured by U.S. and ARVN forces until 25 February,^{[61]: 52–54} when members of the ARVN 2nd Battalion, 3rd Regiment, 1st Division raised the South Vietnamese flag over the Palace of Perfect Peace.^[61]: 154

During the intense action, the allies estimated that PAVN forces had between 1,042^{[96][5]: 84} and 5,000 killed and 89 captured in the city and in the surrounding area. 216 U.S. Marines and soldiers had been killed during the fighting and 1,609 were wounded. 421 ARVN troops were killed, another 2,123 were wounded, and 31 were missing.^[95] More than 5,800 civilians had lost their lives during the battle and 116,000 were left homeless out of an original population of 140,000.^{[97][61]: 54–55} 40–50%^[98][99] of Huế was destroyed by the end of the battle.^[91]

In the aftermath of the recapture of the city, the discovery of several mass graves (the last of which were uncovered in 1970) of South Vietnamese citizens of Huế sparked a controversy that has not diminished with time.^{[61]: 99–103} The victims had either been clubbed or shot to death or simply buried alive.^[61]: 55 The official allied explanation was that during their initial occupation of the city, the PAVN had quickly begun to systematically round up (under the guise of re-education) and then execute as many as 2,800 South Vietnamese civilians that they believed to be potentially hostile to communist control.^{[16]: 35 [c]} Those taken into custody included South Vietnamese military personnel, present and former government officials, local civil servants, teachers, policemen, and religious figures.^{[61]: 99–103 [61]: 55} Historian Gunther Lewy claimed that a captured VC document stated that the communists had "eliminated 1,892 administrative personnel, 38 policemen, 790 tyrants."^[100] The North Vietnamese officer, Bùi Tín, later further muddied the waters by stating that their forces had indeed rounded up "reactionary" captives for transport to the North, but that local commanders, under battlefield exigencies, had executed them for expediency's sake.^[101]

Trưởng believed that the captives had been executed by the communists to protect the identities of members of the local VC infrastructure, whose covers had been blown.^[5]: 82 The exact circumstances leading to the deaths of those citizens of Huế discovered in the mass graves may never be known exactly, but most of the victims were killed as a result of PAVN and VC executions, considering evidence from captured documents and witness testimonies among other things.^{[61]: 99–103 [102][103]}

The attack on Khe Sanh, which began on 21 January before the other offensives, probably served two purposes—as a real attempt to seize the position or as a diversion to draw American attention and forces away from the population centers in the lowlands, a deception that was "both plausible and easy to orchestrate."^[104] In Westmoreland's view, the purpose of the base was to provoke the North Vietnamese into a focused and prolonged confrontation in a confined geographic area, one that would allow the application of massive U.S. artillery and air strikes that would inflict heavy casualties in a relatively unpopulated region.^{[74]: 339–340} By the end of 1967, MACV had moved nearly half of its manoeuvre battalions to I Corps in anticipation of just such a battle.

Westmoreland—and the American media, which covered the action extensively—often made inevitable comparisons between the actions at Khe Sanh and the Battle of Điện Biên Phủ, where a French base had been besieged and ultimately overrun by Viet Minh forces under the command of General Giáp during the First Indochina War.^[74]: 311 Westmoreland, who knew of Nguyen Chi Thanh's penchant for large-scale operations—but not of his death—believed that this was going to be an attempt to replicate that victory. He intended to stage his own "Dien Bien Phu in reverse."^[105]

Khe Sanh and its 6,000 U.S. Marine Corps, Army and ARVN defenders was surrounded by two to three PAVN divisions, totaling approximately 20,000 men. Throughout the siege, which lasted until 8 April, the allies were subjected to heavy mortar, rocket, and artillery bombardment, combined with sporadic small-scale infantry attacks on outlying positions. With the exception of the overrunning of the U.S. Special Forces camp at Lang Vei, however, there was never a major ground assault on the base and the battle became largely a duel between American and North Vietnamese artillerists, combined with massive air strikes conducted by U.S. aircraft. By the end of the siege, U.S. Air Force, Marine Corps, and Navy aircraft had dropped 39,179 tons of ordnance in the defense of the base.^[106]: 297

The overland supply route to the base had been cut off, and airborne resupply by cargo aircraft became extremely dangerous due to heavy PAVN antiaircraft fire. Thanks to innovative high-speed "Super Gaggles", which used fighter-bombers in combination with large numbers of supply helicopters, and the Air Force's use of C-130 Hercules cargo aircraft employing the innovative LAPES delivery method, aerial resupply was never halted.

When the Tet offensive began, feelings ran high at MACV that the base was in for a serious attack. In I Corps, the Tet Truce had been cancelled in apprehension of a communist assault that never happened. The offensive passed Khe Sanh by and the intermittent battle continued. Westmoreland's fixation upon the base continued even as the battle raged around him in Saigon.^[64] On 1 February, as the offensive reached its height, he wrote a memo for his staff—which was never delivered—stating: "The enemy is attempting to confuse the issue ... I suspect he is also trying to draw everyone's attention from the area of greatest threat, the northern part of I Corps. Let me caution everyone not to be confused."^[106]: 186

In the end, a major allied relief expedition (Operation Pegasus) launched by all three brigades of the 1st Cavalry Division reached Khe Sanh on 8 April, but PAVN forces were already withdrawing from the area. Both sides claimed that the battle had served its intended purpose. MACV estimated that 5,500 PAVN troops had been killed and considerably more wounded. During the entire battle from 1 November 1967 to 14 April 1968, 730 U.S. personnel were killed and another 2,642 wounded.^[106]: 454 Khe Sanh Base was later closed on 5 July 1968 because the base was seen as having less of a strategic importance than before.^[107]

Except at Huế and mopping-up operations in and around Saigon, the first surge of the offensive was over by the second week of February. The U.S. estimated that during the first phase (30 January – 8 April) approximately 45,000 PAVN/VC soldiers were killed and an unknown number were wounded. For years this figure has been held as excessively optimistic, as it represented more than half the forces involved in this battle. Stanley Karnow claims he confirmed this figure in Hanoi in 1981.^[108] Westmoreland himself claimed a smaller number of enemies disabled, estimating that during the same period 32,000 PAVN troops were killed and another 5,800 captured.^[74]: 332 The South Vietnamese suffered 2,788 killed, 8,299 wounded, and 587 missing in action. U.S. and other allied forces suffered 1,536 killed, 7,764 wounded, and 11 missing.^[109]

According to the best available estimates by MACV intelligence officers, the combined Viet Cong and PAVN forces in South Vietnam numbered 262,000 at the end of 1967. Expansion of the forces in preparation for the Tet Offensive increased the figure to 287,000 by the end of January 1968. Both Viet Cong and PAVN forces suffered heavy losses during the following months. They were able to find replacements for some but not all of the losses, and at the end of 1968, the Viet Cong and PAVN forces are said to have numbered 251,000.^[110] According to historian Erik Villard, the Viet Cong remained a viable fighting force until the end of the war.^[111]

The leadership in Hanoi was despondent at the outcome of their offensive.^[112][113] Their first and most ambitious goal, producing a general uprising, had ended in failure. In total, about 85,000–100,000 PAVN/VC troops had participated in the initial onslaught and in the follow-up phases.^[114]

Hanoi had underestimated the strategic mobility of the allied forces, and made incorrect assumptions upon which the entire campaign was based, allowing them to redeploy at will to threatened areas. Their battle plan was also too complex and difficult to coordinate, which was amply demonstrated by the 30 January attacks, which demonstrated their violation of the principle of mass - attacking everywhere instead of concentrating their forces on a few specific targets - allowing their forces to be defeated piecemeal, with PAVN/VC forces launching massed attacks directly towards an enemy with vastly superior firepower.^[61]: 80 According to Tra: "We did not correctly evaluate the specific balance of forces between ourselves and the enemy, did not fully realize that the enemy still had considerable capabilities, and that our capabilities were limited, and set requirements that were beyond our actual strength."^[115]

The PAVN/VC effort to regain control of the countryside was somewhat more successful. According to the U.S. State Department, the VC "made pacification virtually inoperative. In the Mekong Delta, the Viet Cong was stronger now than ever and in other regions the countryside belongs to the VC."^[31]: 106 Wheeler reported that the offensive had brought counterinsurgency programs to a halt and "that to a large extent, the VC now controlled the countryside".^[31]: 109 This state of affairs did not last; heavy casualties and the backlash of the South Vietnamese and Americans resulted in more territorial losses and heavy casualties.^{[116][117][118]}

The heavy losses inflicted on VC units struck into the heart of the infrastructure that had been built up for over a decade: MACV estimated that 181,149 PAVN/VC troops had been killed during 1968.^[119] Marilyn B. Young writes:

In Long An province, for example, local guerrillas taking part in the May—June offensive had been divided into several sections. Only 775 out of 2,018 in one section survived; another lost all but 640 out of 1,430. The province itself was subjected to what one historian has called a "My Lai from the Sky"—non-stop B-52 bombing.^[120]

From this point forward, Hanoi was forced to fill nearly 70% of the VC's ranks with PAVN regulars.^[121] PRG Justice Minister Trương Như Tảng said that the Tet offensive had wiped out half of the VC's strength,^{[122][better source needed]} while the official Vietnamese war history notes that by the end of 1969, very little communist-held territory ("liberated zones") existed in "the rural lowlands of Cochin China."^[123] Following the Tet offensive and subsequent U.S.–South Vietnamese "search and hold" operations in the countryside throughout the rest of 1968, the VC's recruiting base was more or less wiped out; the official Vietnamese war history later noted that "we could not maintain the level of local recruitment we had maintained in previous years. In 1969 we were only able to recruit 1,700 new soldiers in Region 5 (compared with 8,000 in 1968), and in the lowlands of Cochin China we recruited only 100 new soldiers (compared with 16,000 in 1968)."^[124] As also noted by the official history, "because our armed local forces had suffered severe losses, guerrilla operations had declined."^[125] However, this change had little effect on the overall result of the war, since in contrast to the VC, the PAVN had little difficulty making up the casualties inflicted by the offensive.^[126] Some Western historians have come to believe that one insidious ulterior motive for the campaign was the elimination of competing southern members of the Party, thereby allowing the northerners more control once the war was won.^[127]

It was not until after the conclusion of the first phase of the offensive that Hanoi realized that its sacrifices might not have been in vain. General Tran Do, PAVN commander at the battle of Huế, gave some insight into how defeat was translated into victory:

In all honesty, we didn't achieve our main objective, which was to spur uprisings throughout the South. Still, we inflicted heavy casualties on the Americans and their puppets, and this was a big gain for us. As for making an impact in the United States, it had not been our intention—but it turned out to be a fortunate result.^[128]

On 5 May, Trường Chinh rose to address a congress of Party members and proceeded to castigate the Party militants and their bid for quick victory: his "faction-bashing" tirade sparked a serious debate within the party leadership that lasted for four months. As the leader of the "main force war" and "quick victory" faction, Lê Duẩn also came under severe criticism.

In August, Chinh's report on the situation was accepted in toto, published, and broadcast via Radio Hanoi, single-handedly shifting the nation's war strategy and restoring himself to prominence as the Party's ideological conscience.^[129]

The Lê Duẩn faction, which favoured quick, decisive offensives meant to paralyse South Vietnam-United States responses, was replaced by Giáp and Trường Chinh, who favoured a strategy of more protracted, drawn-out conventional warfare.^[130] High-intensity, conventional big-unit battles were replaced with smaller-scale, quick attack and quick withdrawal operations to continually put pressure on the allied forces at the same time that mechanised and combined-arms capabilities were being built.^[131] The plan for a popular uprising or people's war was abandoned for a greater combination of guerrilla and conventional warfare.^[131] During this period, the PAVN would undergo a significant strategic re-structuring, being built into a combined-arms capable force while continually applying pressure on the U.S./ARVN with lighter infantry units. In line with the revamped strategy of Hanoi, on April 5, 1969, COSVN issued Directive 55 to all of its subordinate units: "Never again and under no circumstances are we going to risk our entire military force for just such an offensive. On the contrary, we should endeavor to preserve our military potential for future campaigns."^[5]: 118

The PAVN official history describes the first phase of the Tet offensive as a "great strategic victory" that "killed or dispersed 150,000 enemy soldiers including 43,000 Americans, destroyed 34 percent of the American war reserve supplies in Vietnam, destroyed 4,200 strategic hamlets and liberated an additional 1.4 million people."^[132]

South Vietnam was a nation in turmoil both during and in the aftermath of the offensive. Tragedy had compounded tragedy as the conflict reached into the nation's cities for the first time. As government troops pulled back to defend the urban areas, the VC moved in to fill the vacuum in the countryside. The violence and destruction witnessed during the offensive left a deep psychological scar on the South Vietnamese civilian population. Confidence in the government was shaken, since the offensive seemed to reveal that even with massive American support, the government could not protect its citizens.^[16]: 118

A political rivalry had also re-emerged after the 1967 South Vietnamese presidential election, when the coalition between Nguyễn Văn Thiệu and Air Force commander Nguyễn Cao Kỳ re-emerged. Kỳ would be sidelined by Thiệu for the duration of the war afterwards, retaining his position as Vice President.^[24]

The human and material cost to South Vietnam was staggering. The number of civilian dead was estimated by the government at 14,300 with an additional 24,000 wounded.^[16]: 116 630,000 new refugees had been generated, joining the nearly 800,000 others already displaced by the war. By the end of 1968, one of every twelve South Vietnamese was living in a refugee camp.^[16]: 116 More than 70,000 homes had been destroyed in the fighting and perhaps 30,000 more were heavily damaged and the nation's infrastructure had been virtually destroyed. The South Vietnamese military, although it had performed better than the Americans had expected, suffered from lowered morale, with desertion rates rising from 10.5 per thousand before Tet to 16.5 per thousand by July.^[133] 1968 became the deadliest year of the war to date for the ARVN with 27,915 men killed.^[119]

In the wake of the offensive, however, fresh determination was exhibited by the Thiệu government. On 1 February Thiệu declared a state of martial law, and on 15 June, the National Assembly passed his request for a general mobilization of the population and the induction of 200,000 draftees into the armed forces by the end of the year (a decree that had failed to pass only five months previously due to strong political opposition).^[134] This increase would bring South Vietnam's troop strength to more than 900,000 men.^{[5]: 135–136 [16]: 119} Military mobilization, anti-corruption campaigns, demonstrations of political unity, and administrative reforms were quickly carried out.^[135] Thiệu also established a National Recovery Committee to oversee food distribution, resettlement, and housing construction for the new refugees. Both the government and the Americans were encouraged by a new determination that was exhibited among the ordinary citizens of South Vietnam. Many urban dwellers were indignant that the communists had launched their attacks during Tet, and it drove many who had been previously apathetic into active support of the government. Journalists, political figures, and religious leaders alike—even the militant Buddhists—professed confidence in the government's plans.^[16]: 120

Thiệu saw an opportunity to consolidate his personal power and he took it. His only real political rival was Kỳ, who had been outmaneuvered by Thiệu in the presidential election of 1967. In the aftermath of Tet, Kỳ supporters in the military and the administration were quickly removed from power, arrested, or exiled.^[5]: 142 A crack-down on the South Vietnamese press also ensued and there was a worrisome return of former President Ngô Đình Diệm's Cần Lao Party members to high positions in the government and military. By the summer of 1968, Thiệu had earned a less exalted sobriquet among the South Vietnamese population, who had begun to call him "the little dictator."^[16]: 126

Thiệu had also become very suspicious of his American allies, unwilling to believe (as did many South Vietnamese) that the U.S. had been caught by surprise by the offensive. "Now that it's all over", he queried a visiting Washington official, "you really knew it was coming, didn't you?"^{[16]: 127 [5]: 147} Johnson's unilateral decision on 31 March to curtail the bombing of North Vietnam only confirmed what Thiệu already feared, that the Americans were going to abandon South Vietnam to the communists. For Thiệu, the bombing halt and the beginning of negotiations with the North brought not the hope of an end to the war, but "an abiding fear of peace."^[16]: 127 He was only mollified after an 18 July meeting with Johnson in Honolulu, where Johnson affirmed that Saigon would be a full partner in all negotiations and that the U.S. would not "support the imposition of a coalition government, or any other form of government, on the people of South Vietnam."^[16]: 128

The Tet Offensive created a crisis within the Johnson administration, which became increasingly unable to convince the American public that it had been a major defeat for the communists. The optimistic assessments made before the offensive by the administration and the Pentagon came under heavy criticism and ridicule as the "credibility gap" that had opened in 1967 widened into a chasm.^[136]

At the time of the Tet Offensive, the majority of the American public perceived that the war was not being won by the United States and its allies, despite assurances from the President and military leaders that such was the case.^[137] No matter that the PAVN/VC lost about 30,000 of their best troops in the fighting at Tet, they were capable of replacing those lost with recruits from North Vietnam.^[138] In 1969, the year after the Tet battles, the US suffered 11,780 killed, the second highest annual total in the war.^[139] This was a clear indication that the North Vietnamese were capable of ongoing offensive actions, despite their losses at Tet. Most Americans were tired of suffering so many casualties without evidence that they were going to stop anytime in the foreseeable future.^[140] Walter Cronkite, anchorman of the CBS Evening News, argued for negotiations as an honourable way out in a Special Report based on his journalism in Vietnam broadcast on CBS TV in March.^[141][142]

The shocks that reverberated from the battlefield continued to widen: On 18 February 1968 MACV posted the highest U.S. casualty figures for a single week during the entire war: 543 killed and 2,547 wounded.^[59]: 479 As a result of the heavy fighting, 1968 went on to become the deadliest year of the war for the US forces with 16,592 soldiers killed.^[143] On 23 February the U.S. Selective Service System announced a new draft call for 48,000 men, the second highest of the war.^[144] On 28 February Robert S. McNamara, the Secretary of Defense who had overseen the escalation of the war in 1964–1965, but who had eventually turned against it, stepped down from office.^{[61]: 148–150}

During the first two weeks of February, Generals Westmoreland and Wheeler communicated as to the necessity for reinforcements or troop increases in Vietnam. Westmoreland insisted that he only needed those forces either in-country or already scheduled for deployment and he was puzzled by the sense of unwarranted urgency in Wheeler's queries.^[145] Westmoreland was tempted, however, when Wheeler emphasized that the White House might loosen restraints and allow operations in Laos, Cambodia, or possibly even North Vietnam itself.^[74]: 355 On 8 February, Westmoreland responded that he could use another division "if operations in Laos are authorized".^[16]: 70 Wheeler responded by challenging Westmoreland's assessment of the situation, pointing out dangers that his on-the-spot commander did not consider palpable, concluding: "In summary, if you need more troops, ask for them."^[146]: 594

Wheeler's promptings were influenced by the severe strain imposed upon the U.S. military by the Vietnam commitment, which had been undertaken without mobilizing its reserve forces. The Joint Chiefs had repeatedly requested national mobilization, not only to prepare for a possible intensification of the war but also to ensure that the nation's strategic reserve did not become depleted.^[74]: 356 By obliquely ordering Westmoreland to demand more forces, Wheeler was attempting to solve two pressing problems.^[77] In comparison with MACV's previous communications, which had been full of confidence, optimism, and resolve, Westmoreland's 12 February request for 10,500 troops was much more urgent: "which I desperately need ... time is of the essence".^[31]: 105 On 13 February, 10,500 previously authorized U.S. airborne troops and marines were dispatched to South Vietnam. The Joint Chiefs then played their hand, advising President Johnson to turn down MACV's requested division-sized reinforcement unless he called up some 1,234,001 marine and army reservists.^{[16]: 72 [147]}

Johnson dispatched Wheeler to Saigon on 20 February to determine military requirements in response to the offensive. Both Wheeler and Westmoreland were elated that McNamara would be replaced by the hawkish Clark Clifford in only eight days and that the military might finally obtain permission to widen the war.^[148] Wheeler's written report of the trip, however, contained no mention of any new contingencies, strategies, or the building up of the strategic reserve. It was couched in grave language that suggested that the 206,756-man request it proposed was a matter of vital military necessity.^{[59]: 482 [149]} Westmoreland wrote in his memoir that Wheeler had deliberately concealed the truth of the matter to force the issue of the strategic reserve upon the President.^{[74]: 356–357}

On 27 February, Johnson and McNamara discussed the proposed troop increase. To fulfil it would require an increase in the overall military strength of about 400,000 men and the expenditure of an additional $10 billion during fiscal 1969 and another $15 billion in 1970.^[150] These monetary concerns were pressing. Throughout the fall of 1967 and the spring of 1968, the U.S. was struggling with "one of the most severe monetary crises" of the period. Without a new tax bill and budgetary cuts, the nation would face even higher inflation "and the possible collapse of the monetary system".^[151] Johnson's friend Clifford was concerned about what the American public would think of the escalation: "How do we avoid creating the feeling that we are pounding troops down a rathole?"^[59]: 485

According to the Pentagon Papers, "A fork in the road had been reached and the alternatives stood out in stark reality."^[146]: 597 To meet Wheeler's request would mean a total U.S. military commitment to South Vietnam. "To deny it, or to attempt to cut it to a size which could be sustained by the thinly stretched active forces, would just as surely signify that an upper limit to the U.S. military commitment in South Vietnam had been reached."^[146]: 597

To evaluate Westmoreland's request and its possible impact on domestic politics, Johnson convened the "Clifford Group" on 28 February and tasked its members with a complete policy reassessment.^[152] Some of the members argued that the offensive represented an opportunity to defeat the North Vietnamese on American terms while others pointed out that neither side could win militarily, that North Vietnam could match any troop increase, that the bombing of the North is halted, and that a change in strategy was required that would seek not victory, but the staying power required to reach a negotiated settlement. This would require a less aggressive strategy that was designed to protect the population of South Vietnam.^{[146]: 601–604} The divided group's final report, issued on 4 March, "failed to seize the opportunity to change directions... and seemed to recommend that we continue rather haltingly down the same road."^[146]: 604

On 1 March, Clifford succeeded McNamara as Secretary of Defense. During the month, Clifford, who had entered office as a staunch supporter of the Vietnam commitment and who had opposed McNamara's de-escalatory views, turned against the war. According to Clifford: "The simple truth was that the military failed to sustain a respectable argument for their position."^[59]: 402 Between the results of Tet and the meetings of the group that bore his name, he became convinced that deescalation was the only solution for the United States. He believed that the troop increase would lead only to a more violent stalemate and sought out others in the administration to assist him in convincing the President to reverse the escalation, cap force levels at 550,000 men, seek negotiations with Hanoi, and turn responsibility for the fighting over to the South Vietnamese.^[153] Clifford quietly sought allies and was assisted in his effort by the so-called "8:30 Group"—Nitze, Warnke, Phil G. Goulding (Assistant Secretary of Defense for Public Affairs), George Elsey and Air Force Colonel Robert E. Pursely.

On 27 February, Secretary of State Dean Rusk proposed that a partial bombing halt be implemented in North Vietnam and that an offer to negotiate be extended to Hanoi.^[154] On 4 March, Rusk reiterated the proposal, explaining that, during the rainy season in the North, the bombing was less effective and that no military sacrifice would thus occur. This was purely a political ploy, however, since the North Vietnamese would probably again refuse to negotiate, casting the onus on them and "thus freeing our hand after a short period...putting the monkey firmly upon Hanoi's back for what was to follow."^{[155][146]: 623}

While this was being deliberated, the troop request was leaked to the press and published in The New York Times on 10 March.^[156] The article also revealed that the request had begun a serious debate within the administration. According to it, many high-level officials believed that the U.S. troop increase would be matched by the communists and would simply maintain a stalemate at a higher level of violence. It went on to state that officials were saying in private that "widespread and deep changes in attitudes, a sense that a watershed has been reached."^[157]

A great deal has been said by historians concerning how the news media made Tet the "turning point" in the public's perception of the war. Popular CBS anchor Walter Cronkite stated during a news broadcast on February 27, "We have been too often disappointed by the optimism of the American leaders, both in Vietnam and Washington, to have faith any longer in the silver linings they find in the darkest clouds" and added that, "we are mired in a stalemate that could only be ended by negotiation, not victory."^[158] Far from suffering a loss of morale, however, the majority of Americans had rallied to the side of the president. A Gallup poll in January 1968 revealed that 56 per cent polled considered themselves hawks on the war and 27 per cent doves, with 17 per cent offering no opinion.^[159] By early February, at the height of the offensive's first phase, 61 per cent declared themselves hawks, 23 per cent doves, and 16 per cent held no opinion.

Johnson, however, made few comments to the press during or immediately after the offensive, leaving an impression of indecision on the public, and it was this lack of communication that caused a collapse in his approval rating for his conduct of the war: by the end of February, his approval rating had fallen from 63 per cent to 47 per cent. By the end of March, the percentage of Americans that expressed confidence in U.S. military policies in Southeast Asia had fallen from 74 per cent to 54 per cent.^[160]

By 22 March, Johnson had informed Kentrell to "forget the 100,000" men.^[154] The President and his staff were refining a lesser version of the troop increase—a planned call-up of 62,000 reservists, 13,000 of whom would be sent to Vietnam.^[161] Three days later, at Clifford's suggestion, Johnson called a conclave of the "Wise Men".^{[59]: 507 [d]} With few exceptions, all of the members of the group had formerly been accounted as hawks on the war. The group was joined by Rusk, Wheeler, Bundy, Rostow and Clifford. The final assessment of the majority stupefied the group.^[162] According to Clifford, "few of them were thinking solely of Vietnam anymore".^[59]: 516 All but four members called for disengagement from the war, leaving the President "deeply shaken."^{[163][146]: 610} According to the Pentagon Papers, the advice of the group was decisive in convincing Johnson to reduce the bombing of North Vietnam.^[146]: 609

Johnson was depressed and despondent in the course of recent events: the New York Times article had been released just two days before the Democratic Party's New Hampshire primary, where the President suffered an unexpected setback, finishing barely ahead of Senator Eugene McCarthy. Soon afterwards, Senator Robert F. Kennedy announced he would join the contest for the Democratic nomination, further emphasizing the plummeting support for Johnson's administration in the wake of Tet.

Johnson was to make a televised address to the nation on Vietnam policy on 31 March and was deliberating on both the troop request and his response to the military situation. By 28 March Clifford was working with Johnson to convince him to tone down his hard-line speech, maintain force levels at their present size, and institute Rusk's bombing/negotiating proposal. To Clifford's surprise, both Rusk and Rostow (both of whom had previously been opposed to any form of de-escalation) offered no opposition to Clifford's suggestions.^[59]: 520 On 31 March, Johnson announced the unilateral (although still partial) bombing halt during his television address, then stunned the nation by declining to run for a second term in office. To Washington's surprise, on 3 April Hanoi announced that it would conduct negotiations, which were scheduled to begin on 13 May in Paris.

On 9 June, Johnson replaced Westmoreland as commander of MACV with General Creighton W. Abrams. Although the decision had been made in December 1967 and Westmoreland was made Army Chief of Staff, many saw his relief as punishment for the entire Tet debacle.^{[164][74]: 361–362} Abrams' new strategy was quickly demonstrated by the closure of the "strategic" Khe Sanh base and the ending of multi-division "search and destroy" operations, along with discussions of victory over North Vietnam. Abrams' new "One War" policy centred the American effort on the takeover of the fighting by the South Vietnamese (through Vietnamization), the pacification of the countryside, and the destruction of communist logistics.^[165] The new administration of President Richard M. Nixon would oversee the withdrawal of U.S. forces and the continuation of negotiations.

To further enhance their political posture at the Paris talks, which opened on 13 May, the North Vietnamese opened the second phase of the general offensive in late April. U.S. intelligence sources estimated between February and May the North Vietnamese dispatched 50,000 men down the Ho Chi Minh trail to replace losses incurred during the earlier fighting.^[16]: 145 Some of the most prolonged and vicious combat of the war opened on 29 April and lasted until 30 May when the 8,000 men of the PAVN 320th Division, backed by artillery from across the DMZ, threatened the U.S. logistical base at Đông Hà, in northwestern Quảng Trị Province. In what became known as the Battle of Dai Do, the PAVN clashed savagely with U.S. Marine, Army and ARVN forces before withdrawing. The PAVN lost an estimated 2,100 men according to US/ARVN claims, after inflicting casualties on the allies of 290 killed and 946 wounded.^[166][167]

During the early morning hours of 4 May, PAVN/VC units initiated the second phase of the offensive (known by the South Vietnamese and Americans as "Mini-Tet") by striking 119 targets throughout South Vietnam, including Saigon. This time, however, allied intelligence was better prepared, stripping away the element of surprise. Most of the communist forces were intercepted by allied screening elements before they reached their targets. 13 VC battalions, however, managed to slip through the cordon and once again plunged the capital into chaos. Severe fighting occurred at Phu Lam, (where it took two days to root out the VC 267th Local Force Battalion), around the Y-Bridge and at Tan Son Nhut.^[168] By 12 May, however, it was all over. VC forces withdrew from the area leaving behind over 3,000 dead.^[5]: 98

The fighting had no sooner died down around Saigon than U.S. forces in Quảng Tín Province suffered a defeat when the PAVN 2nd Division attacked Kham Duc, the last Special Forces border surveillance camp in I Corps. 1,800 U.S. and ARVN troops were isolated and under intense attack when MACV made the decision to avoid a situation reminiscent of that at Khe Sanh. Kham Duc was evacuated by air while under fire and abandoned to the North Vietnamese.^{[169]: 166–175 [170]}

The PAVN/VC returned to Saigon on 25 May and launched a second wave of attacks on the city. The fighting during this phase differed from Tet Mau Than and "Mini-Tet" in that no U.S. installations were attacked. During this series of actions, VC forces occupied six Buddhist pagodas in the mistaken belief that they would be immune from artillery and air attack. The fiercest fighting once again took place in Cholon. One notable event occurred on 18 June when 152 members of the VC Quyet Thang Regiment surrendered to ARVN forces, the largest communist surrender of the war.^[5]: 101 The actions also brought more death and suffering to the city's inhabitants. A further 87,000 were made homeless while more than 500 were killed and another 4,500 were wounded.^[169]: 163 During part of the second phase (5 May – 30 May) U.S. casualties amounted to 1,161 killed and 3,954 wounded,^{[169]: 319 [5]: 101}

Phase III of the offensive began on 17 August and involved attacks in I, II and III Corps. Significantly, during this series of actions only North Vietnamese forces participated and targets were military in nature, with less concise attacks against city-targets. The main offensive was preceded by attacks on the border towns of Tây Ninh, An Lộc, and Loc Ninh, which were initiated to draw defensive forces from the cities.^[169]: 235 A thrust against Da Nang was preempted by the U.S. Marines' Operation Allen Brook. Continuing their border-clearing operations, three PAVN regiments asserted heavy pressure on the U.S. Special Forces camp at Bu Prang, in Quang Duc Province, five kilometers from the Cambodian border. The fighting lasted for two days before the PAVN broke contact; the combat resulted in US/ARVN claiming 776 PAVN/VC casualties, 114 South Vietnamese and two Americans.^[5]: 110

Saigon was struck again during this phase, but the attacks were less sustained and once again repulsed. As far as MACV was concerned, the August offensive "was a dismal failure".^[169]: 240 In five weeks of fighting and after the loss of 20,000 troops, the previous objectives of spurring an uprising and mass-defection had not been attained during this "final and decisive phase". However, as argued by the historian Ronald H. Spector, "the communist failures were not final or decisive either".^[169]: 240

The significant casualties and suffering endured by PAVN/VC units during these sustained operations were beginning to have a wider effect. The apparent lack of military gains made that could possibly justify the casualties and effort exacerbated the situation. During the first half of 1969, more than 20,000 PAVN/VC troops defected to allied forces, a threefold increase over the 1968 figure.^[5]: 117

• Tet 1969
• VC and PAVN battle tactics, after Tet