North Vietnam’s strategic Spring Offensive in 1972, known in the United States as the “Easter Offensive,” originated in North Vietnamese strategic planning in the aftermath of the South Vietnamese incursion into Laos in early 1971. The offensive was designed to create a change on the South Vietnamese battlefields sufficient to force the United States to accept a diplomatic settlement favorable to North Vietnam. If all proceeded as planned, these terms would include: a complete US withdrawal from the war; communist forces remaining in place in South Vietnam, with no regrouping or return north of the demilitarized zone (DMZ); a coalition government providing a political role for the communists in South Vietnam, which would lead to a communist takeover in the near future; and reparations from the United States.
The offensive continued from late March until October 1972. It triggered a furious response from President Richard Nixon, leading to a massive reinforcement of US air and naval power, a widening of the air war in Operation Linebacker, US Navy operations to mine North Vietnam’s ports and waterways, and eventually to the climactic B-52 raids on the North Vietnamese heartland in December 1972. Nixon’s refusal to accept the prospect of military defeat in Vietnam enabled US and South Vietnamese forces to stymie the offensive, which ended in a military stalemate. The People’s Army of Vietnam (PAVN) offensive did, however, lead eventually to a negotiated settlement in which the United States agreed to a complete withdrawal of its forces from South Vietnam. It was thus a major step toward the final North Vietnamese victory in 1975.
Planning and Preparation
Planning for the offensive by North Vietnam, formally known as the Democratic Republic of Vietnam (DRVN), took place in the context of the US troop withdrawal from the conflict, well underway by 1971. The withdrawal constituted a major element in the complex series of processes by which President Richard Nixon and his key advisor, National Security Advisor Henry A. Kissinger, sought to extract the United States from the conflict in Indochina while maintaining an independent, noncommunist South Vietnam (Republic of Vietnam, or RVN) with President Nguyễn Vӑn Thiệu in power.Footnote 1
From the outset of the administration, Secretary of Defense Melvin R. Laird championed a steady and rapid withdrawal of US troops from a combat role in Vietnam, with the US withdrawal balanced by a simultaneous buildup of South Vietnam’s military capability. Laird and General Creighton Abrams, commander of the US Military Assistance Command, Vietnam (MACV), worked to define and build a program that would equip, expand, and train the Army of the Republic of Vietnam (ARVN), enabling them to pick up the roles of the departing US forces. Laird emphasized Vietnamization, and in fact invented the term, both for domestic political and fiscal reasons: the war in Vietnam was a political liability to the administration, and the drain of US military resources in Indochina jeopardized higher-priority programs essential to countering the ongoing buildup of arms in the Soviet Union. Kissinger argued more than once against these unilateral troop withdrawals because the United States could not then use such withdrawals as bargaining chips in negotiating with North Vietnam. Kissinger’s argument gained little traction with Nixon, and the US troop withdrawals quickly accelerated, propelled by the expectations of the American public.
The four-party negotiations in Paris, opened by the Johnson administration on the eve of the 1968 elections, quickly assumed the role of propaganda theater. There was no prospect of useful diplomacy in that open forum. In August 1969, therefore, the United States and North Vietnam opened secret negotiations in Paris. By August 1971, the negotiators – Kissinger for the United States, and Politburo member Lê Đức Thọ for North Vietnam – had conducted ten rounds of talks. The positions of the two nations gradually converged through unilateral concessions by the United States, but both sides knew that the final decisions would have to await the results of military action. By that same period in mid-1971, the Nixon administration was quietly pursuing closer diplomatic ties with the Soviet Union and an opening to the People’s Republic of China (PRC), expecting these diplomatic steps to exert pressure on the North Vietnamese, who were nearly completely reliant on their communist allies for the supplies needed to carry on the war.
Nixon twice directed cross-border operations to throw the PAVN off balance and buy time for the Vietnamization program to mature – first directing a US–South Vietnamese attack into Cambodia in April 1970, and then sending South Vietnamese forces, heavily supported by US logistics, air support, artillery, and helicopters, into Laos in February 1971. Code-named Operation Lam Sơn 719, the incursion into Laos quickly ground to a halt. The North Vietnamese had anticipated the attack, had deployed forces and logistics in anticipation of its arrival, had built campaign roads, and had developed command structures and defensive strongholds. The South Vietnamese force, facing annihilation, retreated back into South Vietnam, abandoning much of its equipment in a disorderly withdrawal.Footnote 2
Lam Sơn 719 shaped the final phase of the American war in Indochina. Among its immediate effects, Nixon lost all confidence in his theater commander, General Abrams, reaching the point of deciding to relieve Abrams from command for his mismanagement and lack of urgency in directing the operation. The president backed away from this decision, deciding the political price was not worth it, since the US ground war was nearing its end. The South Vietnamese felt that their support from the United States had been inadequate, and the US combatants felt that their often-heroic support of the attacking South Vietnamese forces had been unappreciated. The offensive thus widened the rift between the coalition partners, a rift that would continue to widen as the conflict continued. On the political front, Nixon and Kissinger had planned to use the offensive as the basis for a diplomatic initiative in the secret talks with Hanoi, and met with Xuân Thủy, the titular head of the DRVN delegation to the Paris Peace Talks, on May 31 to offer a prisoners of war (POWs)-for-withdrawal deal. The Politburo, led by Vietnamese Workers’ Party (VWP) First Secretary Lê Duẩn, rejected the offer, continuing to demand the deposition of South Vietnamese President Nguyễn Vӑn Thiệu and communist participation in a coalition government.
But the most lasting effect of the Lam Sơn 719 incursion, perhaps, was its influence on North Vietnamese strategic decision-making. The military logic was straightforward: if the South Vietnamese military performed so poorly with massive American support, how could they possibly pose a threat to PAVN operations once the United States completed its withdrawal? But there were other, far more complicated factors at play as the Politburo planned its campaign strategy for 1972. On the positive side, the United States would conduct a presidential election in November 1972, and North Vietnam had seen in two earlier presidential elections how domestic political events could constrain US military options. That optimistic prospect, though, was overshadowed by the advent of Nixon’s triangular diplomacy, which posed a deadly threat to North Vietnam’s relationships with its superpower sponsors in Moscow and Beijing. Those relationships, which US diplomacy had now placed at risk, would be more vital than ever if the DRVN were to unleash a major offensive.
A PAVN general offensive the following year would inevitably entail great cost and risk in blood and treasure, and possibly in political support from allies. Little is known of the Politburo’s decision-making that led to the offensive, though in conversations with French communists in May 1972, Lê Đức Thọ summarized these discussions as contentious, finally settled by a majority vote. The French Communist Party’s representative in Hanoi, Theo Ponco, had reported back to the party that “unanimity of opinion had not been reached” on the offensive, and that Hanoi’s senior military leader, General Võ Nguyên Giáp, “had reservations … in the event that the destruction of the Hồ Chí Minh Trail made it no longer possible to get the material into the south … despite all the supply buildup precautions taken by the high command.” Thọ summarized that:
we finally reached our decision within the party, and although I cannot tell you how the voting went, the decision was finally made only as a result of a majority vote. It must be said that the young do not see the problem in the same terms as the old, and because of this, differences of opinion are inevitable.
Thọ implied that the decision had been reached under Chinese communist pressure, though this seems doubtful in the face of other evidence that by mid-1971 China was urging the DRVN to accept a negotiated settlement. Asked if North Vietnam could hold out a long time under the bombing and mining operations that by then were underway, Thọ replied:
The situation will be arduous, life will be hard, but we have come through other tests. We are organized to go on for a long time – which does not mean that we enjoy it. What we hope to achieve is President Thiệu’s departure. He, and he alone, stands in the way of the implementation of our plans, which have not changed since 1945.Footnote 3
These risks notwithstanding, the Politburo issued planning directives for the offensive on May 14, 1971. Military planning completed the following month fleshed out the operational concept for the nationwide offensive. The main blow would consist of three combined-armed offensives, each executing a multidivisional attack. The primary blow would come north of Saigon, presenting a direct threat to South Vietnam’s capital. Secondary attacks would be conducted in the Central Highlands and along the DMZ. Once the all-out conventional offensive had knocked South Vietnam’s defenders off balance, the North Vietnamese planners expected to launch attacks on the RVN pacification program, contesting South Vietnam’s control over rural areas, especially in the highly populated Mekong River Delta.Footnote 4 If all went as planned, the third strategic blow would fall in the cities, with uprisings against the Thiệu government.
The campaign was designed to bring a decisive end to the war; the Politburo listed its goals as:
to fundamentally defeat the enemy’s “Vietnamization” strategy, to destroy or cause the disintegration of the bulk of the puppet armed forces, to liberate most of the rural countryside, to intensify the political struggle and the mass uprisings in the cities, and, in coordination with the diplomatic struggle, to force the enemy to admit defeat and accept our demands so that we can secure a decisive victory.
The DRVN leadership noted the integral tie between military action and diplomacy, summarizing that “The battlefield is where victory will be decided. On the basis of the victories we win on the battlefield, we will be able to reach a successful resolution at the negotiating table.”Footnote 5
This operational concept demanded a wholesale reconstruction of the DRVN armed forces, extending from doctrine and organization to battlefield weapons. There was little time to train in the new combined-arms doctrine or with the new weaponry, especially since the new weapons to be assimilated into the PAVN would need to be approved and provided by the Soviet Union, at the end of a supply chain extending back to Moscow. The new weapons – most notably heavy artillery, wire-guided antitank weapons, and shoulder-fired surface-to-air (SAM) missiles – began to reach North Vietnam in November, nearly simultaneously with the opening of the annual infiltration of men and materiel down the Hồ Chí Minh Trail toward the battlefields in South Vietnam.
The challenging climate and topography of Indochina, and the steadily increasing technology and firepower of the combatants, shaped the annual battle along the Hồ Chí Minh Trail. The Laotian dry season extended from November until March and therefore set the timing of the infiltration campaigns. Year after year, North Vietnamese forces extended the road network along the Trail, while their opponents in the US forces increased the sophistication and firepower of the aircraft interdicting the Trail. For the 1971–2 campaign, designated Commando Hunt VII, the US planners brought to bear the massive firepower of B-52 Stratofortress bombers, tactical fighter-bombers from air and naval forces, and increasingly sophisticated gunships, developed from cargo aircraft and armed with varying aerial artillery. The AC-130E gunships fielded in 1971 quickly proved the most effective foe of the movement down the Trail, with night-vision devices, low-light television, infrared and electromagnetic sensors, and with 20mm, 40mm, and 105mm cannon. PAVN sources testify to the effectiveness of the AC-130E, noting its “modern equipment and its logical and intelligent tactics,” and attributing to it about 60 percent of the 4,228 trucks destroyed during the infiltration campaign.Footnote 6
As the PAVN buildup continued, it became increasingly clear to the Nixon White House and to MACV that North Vietnam was planning a major offensive, though its scope, nature, and timing remained unclear. By February 1972 indications of this major offensive led Nixon to direct a reinforcement of B-52s and tactical air forces into theater, add a fourth carrier to the naval force offshore, and remove all sortie restrictions for the tactical air forces and B-52s operating in South Vietnam. These deployments were meant both as a reinforcement for theater forces and as a warning to North Vietnam. Requests by MACV Commander Abrams to conduct airstrikes against PAVN forces moving toward their assembly points, however, were denied by the White House to avoid complicating ongoing diplomacy with the PRC and with the Soviet Union. Nixon and Kissinger were especially intent on minimizing risks to the upcoming summits, planned for Beijing in mid-February and in Moscow in May. In mid-March, Kissinger denied a second request from Abrams, fearing damage to US–PRC relations in the immediate aftermath of the Beijing Summit.Footnote 7
While policymakers in Washington assessed the political–military landscape, so did those in Hanoi. In mid-March, the PAVN General Staff reviewed plans and preparation for the pending campaign, identifying shortfalls in their forces’ capability to attack fortified cities and in the state of the logistics buildup. In a significant late change to earlier plans, the North Vietnamese shifted the primary axis of attack from north of Saigon – Eastern Cochinchina, in DRVN nomenclature – to the area south of the DMZ. This decision reflected the logistics considerations that came into play with the mechanized offensive the PAVN was planning. For the North Vietnamese, resupply of mechanized forces operating north of Saigon would demand a long, contested journey down the Hồ Chí Minh Trail, and there could be no guarantee that sufficient supplies could feed a major attack in that area. While the area south of the DMZ did not pose so immediate a threat to South Vietnam, PAVN forces operating in that area could be more readily resupplied and reinforced. And so the General Staff made an extraordinary decision, shifting priorities in an operation that had been under development for nearly a year. In late March, PAVN forces moved into position for the attack.
As in Washington and Hanoi, leaders in Saigon watched the PAVN buildup and prepared for the offensive to come. From north to south, the RVN stretched over 720 miles (1,160 km) of varying terrain, with enemy forces based all along the RVN’s borders with North Vietnam, Laos, and Cambodia. The exposed borders created an unsolvable vulnerability for the South Vietnamese, stretching their military and enabling the PAVN to select the time of and place for attack. This vulnerability grew as American forces withdrew, leaving South Vietnamese forces to face the relentless pressure of PAVN attacks.
The RVN based its command system on four “Military Regions,” each largely autonomous, each with its distinctive terrain and challenges, and each with a corps command to protect the region. Military Region I (MR I) lay along the DMZ and southward. It encompassed the provincial capital of Quảng Trị, the old imperial city of Huế, and the major port and airfield at Đà Nẵng. The region was defended by General Hoàng Xuân Lãm’s I Corps. Under Lãm’s command were the 3rd ARVN Division along the DMZ, the 1st ARVN Division to the west of Huế, and the 2nd ARVN Division defending the southern three provinces within the region. In addition, the 3rd ARVN Division exercised operational control over two marine brigades stationed in the northwest sector, protecting the region against a flanking attack from the rough terrain around the border with Laos.
MR II, under the command of Lieutenant General Ngô Du, defended the Central Highlands, as well as several provinces on the coastal lowlands from Binh Định province south to Bình Thuận province. The two ARVN divisions defending the corps tactical zone were the 22nd, responsible for the northern part of the region and based in Kontum, and the 23rd, responsible for the southern section and based in Ban Mê Thuột. MR II forces also included eleven Ranger battalions along the Cambodian border.
MR III encompassed the area surrounding Saigon; its order of battle contained three divisions: the 5th, 18th, and 25th, along with three Ranger groups. MR IV bore responsibility for security of the Mekong Delta, the most populous area of the country and its agricultural breadbasket. Three ARVN divisions – the 7th, 9th, and 21st – were under IV Corps command, along with 200,000 territorial troops, by far the largest force of its kind in the four Military Regions.
While ARVN divisions formed the backbone of the corps’ defense capability, they were territorial forces, trained to fight in a given area. Rarely were they called upon to operate outside their normal territories, and invariably such deployments paid a high price in effectiveness. South Vietnam complemented these territorial capabilities with a strategic reserve of elite forces – marines, Airborne, and Rangers – personally allocated by President Nguyễn Vӑn Thiệu to meet emergencies as they arose on the battlefield.
Opening of the Spring Offensive
The offensive opened on March 30, 1972 with a devastating artillery and infantry assault by the 304th and 308th PAVN Divisions, spearheaded by tanks, on ARVN outposts along the DMZ. The blow fell on the ARVN 3rd Division, constituted the previous October, inexperienced and in the midst of a troop rotation ordered by the divisional commander, Brigadier General Vũ Vӑn Giai, to orient his new division to its operating area. By the evening of April 1, General Giai had been forced to order a general withdrawal of his forces south of the Cửa Việt River to establish a new line of defense. That line failed the following day when the 56th ARVN Regiment surrendered at the linchpin of the defensive perimeter, Camp Carroll.Footnote 8
The second arm of the PAVN offensive moved into action north of Saigon on April 2, with a diversionary attack against Tây Ninh. Two days later, the PAVN 5th Division followed with an attack against the district military base at Lộc Ninh, overrunning the base on April 6. Meanwhile the PAVN 9th Division moved toward its assault on the provincial capital, An Lộc, while the PAVN 7th Division established blocking positions on Route 13 south of the city. Thiệu reinforced the garrison with a brigade of paratroopers from the strategic reserve, but in early April it appeared that PAVN forces would sweep up An Lộc and move on to pose a direct threat to Saigon.
During that same period in early April, the PAVN opened their offensive in the Central Highlands with assaults on the firebases shielding the western flank of the major bases in the region – Pleiku and Kontum. John Paul Vann, the senior military advisor to ARVN General Du, responded personally, ferrying in supplies to the bases under attack, establishing a hands-on direction of the battle that would define his role throughout the campaign.
Nixon considered the North Vietnamese offensive a direct threat both to his foreign policy objectives and to his domestic political future, and responded decisively once the PAVN invasion was confirmed. As news of the PAVN attacks arrived, he declared to Kissinger that “we’re playing a much bigger game – we’re playing a Russia game, a China game, and an election game and we’re not gonna have the ARVN collapse.”Footnote 9 His response to the offensive was heightened by his mistrust of the senior officials in the Defense Department and the military chain of command. After years of working with US Secretary of Defense Melvin Laird on force withdrawals and theater strategy, Nixon had no confidence in Laird’s willingness to respond vigorously to the PAVN attacks. Similarly, the president had lost confidence in theater commander Abrams during the previous year’s major campaign, Lam Sơn 719, in terms of both reacting effectively to changes in the battle and keeping the White House informed accurately on the course of the fighting. Convinced that Abrams had been in command too long, that he was “tired, unimaginative,” Nixon sent Air Force General John Vogt out to Saigon in command of 7th Air Force. Meeting with Vogt on April 6, Nixon sent him out to his new position with the presidential direction that “What’s going to determine this is not what Abrams decides, because he’s not gonna take any risks at this point, but what you’ll decide.”Footnote 10 Therefore, through the months that followed, Nixon, Kissinger, and increasingly Deputy National Security Advisor Major General Alexander M. “Al” Haig managed the White House response to the PAVN offensive through the Chairman of the Joint Chiefs of Staff (CJCS) Admiral Thomas H. Moorer, often placing Moorer in an uncomfortable position between the White House and his direct supervisor, Secretary of Defense Laird. Upon his arrival in Saigon on April 10, Vogt managed the air war and, at Moorer’s request, ensured that the White House was kept informed of the results of ongoing air operations.Footnote 11
While restructuring his chain of command to and in MACV, Nixon took direct control over the American military response, ordering airstrikes on SAM sites in the area just north of the DMZ. He further authorized a sustained air offensive in the North Vietnamese panhandle up to the 18th parallel, later extended further north to the 20th parallel and named Operation Freedom Train. For the North Vietnamese, surprised at Nixon’s rapid and aggressive response, this return to sustained bombing north of the DMZ, beginning with a highly successful attack on SAM defense forces on April 6, marked the opening of the Second Air War.
Nixon’s most significant decision in the immediate response to the offensive, however, was to order a massive reinforcement of air and naval forces in Indochina – tactical fighter units, aircraft carriers, naval gunfire support, and B-52s. When the offensive opened in late March, the navy had two carriers conducting operations off Indochina. Within weeks, there were six carriers on the line. The February deployment ordered by Nixon had dispatched twenty-nine B-52s to Andersen Air Force Base, Guam. With the invasion underway, the president sent another forty-eight of the heavy bombers into the conflict. Meanwhile, marine and air force fighter squadrons returned to recently closed bases in Thailand. Air force sorties doubled with the reinforcing aircraft, from an average of 204 sorties a day in March to an average over 400 a day in late April.
For Nixon, the direct response to the North Vietnamese forces was only one play in his bigger game. Beyond stymying the PAVN attack, the president thought it imperative to send a message of strength and commitment to Hanoi and to Moscow, and to send it with the most powerful weapon available: B-52 strikes in North Vietnam. Nixon believed these strikes to be a vital part of his great-power diplomacy and, as Kissinger later summarized, “a warning that things might get out of hand if the offensive did not stop.” General Abrams, however, considered these strikes a dangerous diversion of his most precious resource, the B-52s that he used as a mobile reserve, compensating for the combat power lost as US ground forces withdrew from the conflict. Worse still, each B-52 raid demanded extensive support by air force and navy fighters providing escort, chaff corridors, and defense suppression, reducing the number of attack sorties available to Abrams. Nixon overrode Abrams’ protests, and B-52s struck the North on April 10 and 13.
The president then directed a massive raid against Hải Phòng to coincide with Kissinger’s trip to Moscow on April 16. Abrams again vehemently opposed the strike, summarizing with the comment that “In my view the risks have remained unchanged and they are grave.” Nixon considered this a means of Abrams ensuring that the president would receive the blame if the PAVN offensive succeeded, and he and Kissinger decided to cancel the strike with the bombers airborne, an hour from their target area. However, Admiral Moorer intervened with the argument that “The military people out in Vietnam already think we are crazy. If we scuttle this flight and have them jettison the bombs … then if there were any doubts about us being crazy then they would be convinced of it.”Footnote 12 Nixon concurred, and the B-52 raid proceeded against Hải Phòng as scheduled. The following day, US forces attacked Hanoi for the first time since 1968. The dispute with Abrams was enough to persuade Nixon and Kissinger to send Haig to Indochina, to make clear to Abrams the broader purposes behind the B-52 strikes against North Vietnam. Additionally, Haig would serve as Nixon’s eyes in theater, providing the White House an independent assessment of the conflict. While the immediate crisis between the president and the theater commander subsided, at least on the surface, the issue continued to exacerbate the already weak relationship between them as the White House directed two more B-52 attacks in April, both against the Thanh Hóa area.Footnote 13
On the Southern battlefronts, after the initial surges across the DMZ and against An Lộc, PAVN forces stalled, unprepared to take advantage of success. It was a pattern they would repeat on all fronts during the offensive. The PAVN’s inability to exploit opportunities reflected several factors: a rigid planning and command structure, logistics limitations, limited training in combined-arms tactics, and the increasing effectiveness of US air attacks. That pattern caused a fatal delay to PAVN efforts to take An Lộc quickly. As the PAVN 9th Division deployed into position for an attack that would exploit the early weakness of the ARVN garrison, it hesitated for nearly a week, awaiting resupply. The attack finally opened on April 13, only to be halted by ARVN forces, leaving the city divided between ARVN forces in the south and PAVN in the north. Two days later the PAVN launched another attempt at overrunning the city, but this attack failed as well, and PAVN forces settled into a siege of the city, denying both road access and aerial delivery of supplies to the defenders as they awaited reinforcements.
That same pattern of early success followed by a hesitant follow-up similarly afflicted PAVN forces along the DMZ. Seemingly unstoppable during the first days of the offensive, by early April they were at a halt, awaiting the supplies and reinforcements necessary to overcome the reconstituted ARVN defenses along the Cửa Việt River, under nearly continuous air attack by air force and navy fighters and B-52s. South Vietnamese forces on the defensive, however, failed to take advantage of the PAVN pause, instead exhausting the troops along the DMZ with futile attempts to take the offensive.
Meanwhile, as Thiệu committed South Vietnam’s strategic reserve forces into the battle in MR I, the divisional command structure under General Giai became increasingly ineffective. Ironically, it was the flow of reinforcements deployed under Thiệu’s orders that overwhelmed General Giai’s command. Formally, Giai commanded two regiments from the 3rd Division, and exercised operational control over two marine brigades, four Ranger groups, one armored brigade, and the territorial troops in the area. In a long-standing practice across the RVN’s armed forces, the marines and Rangers only formally acknowledged Giai’s authority, in practice reaching back to their headquarters in Saigon for direction. This deeply embedded practice led not just to inefficiency, but to corrosive mistrust and confusion, leading finally to a breakdown in the ARVN defenses.
The gradual deterioration in the South Vietnamese defenses accelerated in late April, as the PAVN resumed their offensive with a flanking attack on April 27, intended to cut off South Vietnamese forces from their supply routes to the south. By April 29, the defenses had contracted to a narrow corridor along Route 1; the following day, the Republic of Vietnam Armed Forces (RVNAF) defenses collapsed, with RVNAF forces streaming south along Route 1. On the afternoon of May 1, American advisors evacuated the provincial capital, Quảng Trị, by helicopter, and the PAVN overran the city. For the first time in the war, the communist forces had taken a provincial capital. Worse, it appeared that the path was open to a rapid advance to the south and the fall of the ancient imperial city of Huế, portending the success of the PAVN offensive in MR I and perhaps the fall of Thiệu, with disastrous consequences for the RVN and the war effort.
Those days in late April saw the PAVN offensive in the Central Highlands close on the major ARVN bases, culminating in an attack by the PAVN 2nd Division on Tân Cảnh on April 24. There the PAVN unveiled another relatively advanced weapon, the Soviet AT-3 wire-guided missile, as they opened their attack. The impact of the AT-3 warhead on the command bunker incapacitated the 22nd Division commander, Colonel Lê Đức Đạt, and through the rest of the day he took no part in the defense of his garrison. That night the PAVN deployed medium tanks on the attack, the first time the North Vietnamese had used armored forces in MR II. The shock of these advanced weapons again disintegrated the ARVN defenses. Tân Cảnh fell that night, as helicopters evacuated the US advisory team. The way now lay open to Kontum, if the PAVN could seize the opportunity.
With the 22nd Division effectively out of action, Thiệu took the extraordinary step of deploying the 23rd Division northward into Kontum, with ARVN Colonel Lý Tòng Bá commanding a force of ARVN infantry, four battalions of Rangers, an Airborne brigade, and sector forces. Vann set to work summoning US air support, buying time for RVNAF forces to restore their defenses. Meanwhile he sent a stream of reports to Abrams focusing on corps commander Lieutenant General Ngô Du’s deficiencies in command, and on the disintegration of command cohesion in MR II.
The Path to Linebacker
As April turned to May, North Vietnam had reached the high-water mark of its Spring Offensive. South Vietnam’s forces had been routed in MR I, with the PAVN moving south to threaten Huế, and with the ancient capital in a state of panic. Kontum and An Lộc each lay under siege, both awaiting PAVN attacks threatening to deliver the coup de grâce once siege warfare had sufficiently weakened the RVNAF garrisons.
General Abrams had sent periodic assessments of the situation back to Washington since the opening of the offensive two months earlier, uniformly optimistic through late April. With the fall of Quảng Trị on May 1, however, the MACV commander submitted a somber summary of the battle, summarizing that:
I must report that as the pressure has mounted and the battle has become brutal the [ARVN] senior leadership has begun to bend and, in some instances, break. In adversity it is losing its will and cannot be depended on to take the measures necessary to stand and fight. … In light of this there is no basis for confidence that Huế or Kontum will be held.
Abrams and the US ambassador to South Vietnam, Ellsworth Bunker, took the same message to President Thiệu, who as a result replaced General Lãm as MR I commander on May 3 with General Ngô Quang Trường. Trường had expected the appointment, and responded rapidly, decisively, and successfully in bringing calm to a chaotic situation. He did so by restructuring the defenses north of Huế, by developing an effective system to allocate the vast quantities of firepower offered by US air and naval support forces, and most of all by infusing new spirit and determination into the city and its defenders.
The military crisis in Indochina played out against a backdrop of high-stakes political and diplomatic activity, critical to the success of Nixon’s foreign policy and political survival. Three weeks ahead loomed the Moscow Summit, the keystone of Nixon’s goal of reshaping superpower relationships among Moscow, Beijing, and Washington. Beyond the summit stretched the electoral campaign that would consume the attention, and limit the options, of the White House until the November 9 election. Always committed to acting from a position of strength, Nixon decided to order a massive strike against Hanoi for early May. Over time and in consultation with Kissinger, that idea gradually evolved into a blockade of North Vietnam, and finally to a plan to mine North Vietnam’s harbors.
On May 4, Nixon gathered with his most trusted advisors – Kissinger, Haig, and Secretary of the Treasury John Connally – to talk through his options. Nixon decided to order an all-out air offensive against North Vietnam and to mine the North Vietnamese ports. The air campaign would be designed to isolate North Vietnam from its sources of supply in the Soviet Union and China, and cut off the flow of supplies from North Vietnam to the combat zones in South Vietnam.
The conversation culminated with Admiral Moorer being summoned to the White House and directed to update the long-existing plans for mining North Vietnam’s ports, and to do so without either consulting or informing the secretary of defense or the MACV commander. The process by which this momentous decision was reached was a remarkable testimonial to the concentration of decision-making in the Nixon White House, and the dysfunctional relationship between the president and the military chain of command. Nixon convened the National Security Council (NSC) to discuss the situation in Indochina on May 8, and that afternoon ordered the mining of North Vietnam’s ports and the opening of a sustained attack on North Vietnam’s transportation system.
Linebacker and Pocket Money
Nixon addressed the nation on May 9 to announce his decisions, carefully timing the speech to occur simultaneously with the mining operation closing the port of Hải Phòng. In a somber tone, he summarized his strategy: “There is only one way to stop the killing. That is to keep the weapons of war out of the hands of the international outlaws of North Vietnam.” He followed with the stunning announcement of the mining of North Vietnam’s ports, and the sustained attack on the DRVN’s road and rail systems. But obscured by the tough tone and military measures, Nixon offered new negotiating terms that earlier would have been considered a surrender: upon the return of American POWs and an internationally supervised ceasefire, the United States would withdraw its forces from Vietnam within four months. Finally, Nixon spoke directly to the leadership in the Soviet Union, emphasizing that “We, the United States, and the Soviet Union, are on the threshold of a new relationship that can serve not only the interests of our two countries, but of world peace.” Nixon made clear that if the Soviets decided to derail that new relationship, the responsibility would be theirs.
As Nixon spoke, half a world away navy A-6s and A-7s mined Hải Phòng Harbor. In succeeding days, the navy shut down every port in North Vietnam and extended the mining operations to North Vietnam’s inland waterways. The navy conducted the mining of the ports through Operation Pocket Money, periodically replenishing the mines through the following months, and supplementing the mining with patrolling by ship, aircraft, and helicopter. The operation would continue until the following January.
Nixon and Kissinger were intent on avoiding the creeping incrementalism of President Lyndon Johnson’s earlier air offensive, Operation Rolling Thunder, and immediately after the mining operation ordered attacks taking the war directly into the enemy’s heartland. Kissinger called Moorer on the evening of May 8 to suggest a B-52 raid on Hanoi immediately after the mining operation. Moorer assured him that there was already a plan in motion, that Vogt had suggested a mass raid with precision bombs against Hanoi. The conversation set in motion the greatest air battle of the war.
On May 9, the CJCS named the air campaign Operation Linebacker, replacing the earlier Operation Rolling Thunder Alpha designation. The new name was designed to emphasize the differences between this campaign and Lyndon Johnson’s predecessor. Nixon expected this air campaign to apply relentless, ceaseless pressure to North Vietnam’s government, populace, and military forces, especially the logistics system. There would be no gradual escalation, but an immediate and overwhelming series of attacks. The highly centralized and episodic targeting process used under Johnson would be replaced by military decision-making, enabling the commanders in theater to shape the campaign and select the targets. Moreover, Linebacker would take advantage of precision-guided weapons, which offered orders of magnitude more effectiveness against fixed-point targets than the visually aimed ordnance used in Rolling Thunder.
On May 10, the air force launched a major strike against Hanoi, and the navy launched three successive waves against Hải Phòng and the ports to its north. The Vietnam People’s Air Force (VPAF) responded aggressively to challenge the US strikers. Two US fighters were shot down, but at a prohibitive cost to the North Vietnamese of eleven aircraft. In its aftermath, DRVN Defense Minister Võ Nguyên Giáp reviewed the day’s activities and directed a change in tactics for the VPAF, toward “secret, surprise attacks sure to achieve victories.” There would be no more mass confrontations between American and North Vietnamese fighter forces.
The day’s strikes set patterns for the US Air Force and Navy that would persist until the end of the Linebacker operation, months away. Under the direction of General Vogt, the air force structured its strikes around laser-guided weapons, now used for the first time in heavily defended areas. Vogt orchestrated these air force strikes with layered defenses for the strike aircraft – fighter escorts, chaff corridors to blind DRVN radars, aircraft to suppress SAM defenses, standoff electronic intelligence, and jamming support – flown from bases all across Southeast Asia. Conceptually powerful, these packages were complex and fragile, susceptible to breakdowns in coordination in the chaotic and dangerous environment over North Vietnam. By contrast, navy strikes, flown from carriers offshore, were generally formed from aircraft from a single air wing, simplifying planning and orchestration of the attacks. However, the navy had not yet adopted the laser-guided weapons that were so critical to air force attacks.
Operation Linebacker encountered many of the difficulties faced in the earlier Rolling Thunder campaign. Admiral Moorer decided to retain the system of route packages, or packs, that had shaped Rolling Thunder. They were designed to provide separation between air force and navy strike forces, but, in doing so, they practically eliminated any prospect of coordinated or massed attacks by US air forces. Route Pack 1, just north of the DMZ, would be the responsibility of MACV. Route Packs 2, 3, and 4, extending northward along the North Vietnamese panhandle, would be the domain of the navy. Route Pack 5 in the northwest would fall to the air force, operating out of Thailand. Route Pack 6 extended northeast out of Hanoi, covering the main logistics ties to China, and would be divided between the air force and the navy. Although defended by Laird and Moorer, the Route Pack structure constantly irritated the White House, where Nixon and Kissinger considered it a victory of service parochialism over military effectiveness.
The Linebacker operational environment proved to be as demanding as in Rolling Thunder. Indochina’s weather patterns precluded the sort of relentless attacks envisioned by Nixon, and the use of precision weaponry brought additional complexity and sensitivity to weather conditions. The demand for air support in the still-intense battles in the South created a continual tension with the requirements for strikes in the North, with Vogt trapped between Nixon’s urgency for Linebacker sorties there and Abrams’ demand for air-support sorties in the South. North Vietnam’s logistics networks were widespread and redundant, and the North Vietnamese government would spare no effort in mobilizing the population to ensure the effectiveness of their transportation system.
The diplomatic play defined by Nixon’s “triangular diplomacy” began immediately after the May 9 strikes. North Vietnam appealed to the Soviet Union to cancel the upcoming summit with Nixon and to send a flotilla into Hải Phòng Harbor in a direct military challenge to the American mining. Soviet leader Leonid Brezhnev convened the Soviet Politburo to address the decision. In the end, the Soviet Union decided to proceed with the summit, prioritizing its budding relationship with the United States over its relationship with its troublesome ally in Hanoi. The PRC faced no similar pressure, with its summit with Nixon already accomplished, but confined its response to routine diplomatic protests and to sending minesweepers to assist North Vietnam. In Nixon’s phrase, the communist superpowers decided that they had “bigger fish to fry” in their warming relations with the United States. Although the Soviet Union and PRC continued to provide the DRVN with weapons and supplies, they would not jeopardize their larger strategic interests.
North Vietnam’s offensive crested in mid-May, just as the Linebacker air campaign was gathering strength. North of Saigon, the PAVN siege of An Lộc was broken on May 4, at least partially, when the US Air Force developed tactics for high-level airdrops into the city. A week later, US and RVNAF intelligence provided warnings of a pending climactic attack on the city by the besieging PAVN forces. The attack opened on May 11 with a massive predawn artillery barrage, followed by deployment of a small armored force and a massive infantry assault. Taking full advantage of advance warning, Senior Advisor Lieutenant General James Hollingsworth marshaled massive, nearly continuous B-52 strikes, continuing the strikes throughout the day. Support by US gunships, B-52s, and tactical air bludgeoned the assault into a standstill, with the PAVN seizing two new sectors in the city but posing no threat to dislodge the ARVN defenders. A weaker attack two days later served only to add to the number of casualties on both sides. The PAVN called off the offensive on May 15 and adopted a blocking strategy designed to occupy RVNAF forces, drawing them away from populated areas to permit attacks on the pacification program. While An Lộc would stay in South Vietnamese hands, the terrain north of the city would remain under communist control until the end of the war, and through the ceasefire that followed.
Figure 9.1 A US Air Force team refueling on its way to North Vietnam during Operation Linebacker (October 1972).
In the Central Highlands, during the weeks of late April and early May, PAVN forces deployed into positions around Kontum, preparing for an armored attack to overwhelm the city’s defenders, who were led by the incompetent General Du. On May 10, President Thiệu replaced him with armor commander Lieutenant General Nguyễn Vӑn Toàn. By that point the defenses had been reestablished under Colonel Lê Đức Đạt, while Vann had personally assumed control of the B-52 sorties sent to MR II. The PAVN launched its first major assault on May 14, halted that night by a B-52 attack. The PAVN continued its attacks intermittently until May 29, but effective ARVN defenses, buttressed by B-52, gunship, and tactical air support, gradually weakened PAVN forces, allowing Vann to terminate the tactical emergency on May 31. Vann, who died in a helicopter accident on the night of June 10, had played a prominent role in the defense of Kontum and the combat in the Central Highlands.Footnote 14
The DRVN Responds to the Second Air War
As these events transpired in the South, the North Vietnamese struggled to respond to Nixon’s all-out air war. North Vietnamese leaders had seriously underestimated Nixon’s response to their offensive, and the DRVN was unprepared for Operation Linebacker. The Politburo directed an assessment of the situation after the initial air attacks, measuring current stockpiles, the state of the transportation system, and the measures that would be required to continue the struggle through the coming months.Footnote 15 The report was ready a week later, and its assessment was grim: “Our stock levels are low and we must be very economical in our expenditures of them if they are to last us through the next several months.” Gasoline and food stocks were critical and would require careful rationing.
The assessment stressed the overriding priority of the transportation system: “At present the work of supporting transportation and supply operations is our central, Number One priority. This work is of the greatest importance for us on all fronts: military, economic, political, and diplomatic. It is one of the conditions that will decide our success or failure in production and in battle.” Air defenses would be deployed to protect the transportation network, especially the roads and rails bringing supplies from China, and the routes from the heartland down to the battle area. The DRVN leadership persuaded the PRC to deploy oil pipelines to the DRVN border, to connect with other pipelines constructed by Hanoi to move the fuels southward toward the DRVN heartland and the battle area. Once finished, this network would remove a major load from the DRVN’s transportation network and facilitate the truck-borne traffic southward toward the battle areas. Meanwhile, both communist superpowers agreed to provide defensive weaponry to the North Vietnamese. Finally, the regime intensified civil defense measures, evacuating the population of Hanoi except for those involved in production, defense, or administration, and conducting a massive effort to build air-raid shelters for those remaining in the city.
North Vietnam’s lack of preparedness for the air offensive extended to its air defenses as well. In the years since Rolling Thunder, experienced SAM operators had rotated to other assignments. Additionally, PAVN air-defense forces had not kept abreast of the evolution of US electronic jamming equipment; nor were they familiar with a new generation of tactical aircraft and tactics in US air operations. In response, the DRVN accelerated upgrades to its air defenses, adopting optical guidance systems to counter the new American jamming systems.
As the air offensive battered the DRVN transportation network, especially on the northeast corridor toward China, the North Vietnamese developed a shuttle system integrating road and rail transport, working around the devastation caused by the air attacks. As the attacks continued, truck traffic shifted to predominantly night operations, and the North Vietnamese established a major storage and transshipment depot near the Chinese border. The DRVN mobilized its workforce even more thoroughly than earlier in the war, taking advantage of the manpower freed up by the destruction of most industries, and used this workforce to keep the roads open. At the outset of the campaign, the United States had estimated it would take four to six months for the DRVN to shift its logistics system away from the ports and onto roads and rail. As often happened, US planners underestimated the adaptiveness and organizational capacity of the DRVN bureaucracy: the massive effort to transform the logistics system took weeks, not months.
But there were many miles from the logistics depots at the Northern border to the battlefields in the South, and US air forces and naval gunfire contested every mile. Air force and navy air attacks steadily pounded the infrastructure and movement of supplies down the North Vietnam panhandle south of Hanoi. It was war by attrition, with the North Vietnamese air defenses destroying many of the attacking aircraft, but at the cost of heavy losses of their own in men and materiel.
By late May, the PAVN thrusts in the Central Highlands and north of Saigon had been countered, leaving the battlefields north of Huế as the last active arm of the DRVN’s great Spring Offensive. With the threats to the South now quieted, the United States could concentrate its firepower against PAVN forces in MR I, and Thiệu could commit the RVNAF’s strategic reserve to defend Huế. Nonetheless, the Politburo, intent on the political basis of the battle, insisted on continued attacks. Finally, on June 26, the last PAVN attack on the defenses of Huế failed quickly. In its aftermath, South Vietnamese forces, supported by massive US naval and air support, launched a counteroffensive to retake Quảng Trị. This city, reduced largely to rubble, was purely a symbolic and political target, but it became the focus of a months-long campaign steadily reinforced by both sides. On September 16, South Vietnam reclaimed the city, and the only provincial capital to fall in the DRVN’s offensive was back in South Vietnamese hands.
South Vietnam’s victory at Quảng Trị forced the DRVN Politburo to reassess its negotiating strategy and its objectives, setting the course for the settlement that would end the American role in the war. With the stagnation of the Spring Offensive and the loss of its most visible triumph, the Politburo’s subcommittee responsible for advising on the peace negotiations recommended that the Politburo lower its demands for the peace settlement. In a subsequent Politburo meeting, First Secretary Lê Duẩn argued that the DRVN needed to focus on its primary objective, America’s complete withdrawal from the war, contending that this achievement would inevitably lead over time to the collapse of South Vietnam. The Politburo agreed to a “loosening” of the political terms of the settlement, no longer demanding that Thiệu be removed from office and a coalition government established.
Kissinger met with North Vietnamese negotiators in July, August, and September, with both sides working to reach an agreement before the November 7 presidential election.Footnote 16 The sides made measurable progress toward agreement during these rounds, and both expected major movement when they met in October. As the October talks neared, Nixon and Kissinger discussed their strategic goals for the endgame of the war and with respect to South Vietnam. Nixon emphasized that “we cannot continue to allow Vietnam to inhibit us in any way as we develop and play our big game out – the game with the Russians and the Chinese and the Japanese and the Europeans – and the big game now becomes enormously important.” He and Kissinger concluded that South Vietnam had perhaps a 25 percent chance of survival after the United States withdrew, and that in that context the most important thing, to quote Nixon, was “the bigger subject: How does the United States look in the way it handles this goddamn thing?” The United States would have to be seen to have “gone the extra mile” in supporting South Vietnam, but in the end would have to withdraw from the war and avoid a postwar entanglement in Indochina in order to achieve Nixon’s higher-priority international goals.Footnote 17
As both sides had anticipated, the October round of negotiations led to an agreement between North Vietnam and the United States, as Lê Đức Thọ tabled a draft settlement that would permit Thiệu to remain in office. The North Vietnamese political concessions allowed Kissinger and Lê Đức Thọ to agree to peace terms on October 20, 1972, and Nixon to suspend Operation Linebacker on October 22. American air forces would continue to attack North Vietnam but would be limited to targets below the 20th parallel. Ironically, Nixon issued this directive on the same day that South Vietnamese President Thiệu forcefully rejected the terms reached by Lê Đức Thọ and Kissinger.Footnote 18
Linebacker II: The “Christmas Bombing”
Thiệu’s rejection of the peace settlement in late October set the stage for a protracted search for an agreement that both North and South Vietnam would accept, with the United States – or more specifically, Kissinger – now trapped between the Vietnamese parties. Kissinger and Lê Đức Thọ underwent two arduous negotiating rounds after the presidential elections, from November 20–4 and again December 5–13, coming close to a settlement but with the negotiations finally foundering on essentially symbolic issues.
Nixon met with Laird and the JCS on November 30 to direct planning for two contingencies: for a North Vietnamese refusal to sign a peace agreement, and for a North Vietnamese violation of the settlement if an agreement was reached. On December 6, Haig forwarded Nixon’s direction that the JCS form a “tightly controlled planning group” for “an immediate target-planning effort for North Vietnam.” Haig provided the planning framework for the strikes, emphasizing the psychological effects of the bombing:
The strike plan … must be so configured as to create the most massive shock effective in a psychological context. There is to be no dissipation of effort through scattered attacks against a number of varied targets, but rather a clear concentration of effort against essential national assets designed to achieve psychological as well as strategic results.Footnote 19
On December 13, Kissinger and Lê Đức Thọ agreed to suspend the peace talks and return to their respective capitals for consultation. Nixon, Kissinger, and Haig met in the Oval Office the following morning to decide on their next moves. Angry and frustrated with both Vietnamese parties, Nixon reluctantly agreed to an all-out bombing campaign against North Vietnam, employing B-52s for the first time over North Vietnam’s heartland. This coercive assault against the North would be coupled with a less vivid but equally powerful campaign of coercion against South Vietnam, as the White House threatened to cut off diplomatic, economic, and military support for its long-term ally. The United States, to use Nixon’s phrase, had found it necessary to “turn on both sides” to find an exit from the war. Nixon and his advisors decided to conduct an all-out bombing campaign against North Vietnam until December 28, and if there was no progress toward a settlement by then, to transition to a bilateral deal with the North Vietnamese. In return for the release of the American POWs held by North Vietnam, the United States would end the bombing and withdraw its forces.Footnote 20
North Vietnam’s political and military leadership had long expected B-52 raids against Hanoi and Hải Phòng, and as early as January 1969 issued a defense plan against such attacks. But when the B-52s attacked the North at the opening of the Easter Offensive, the DRVN’s air defenses proved unable even to detect the B-52s, given the intense jamming and chaff that shielded the bombers. At that moment the nation was helpless in the face of a B-52 attack against the heartland. Consequently, North Vietnam’s Air Defense Service performed a rigorous self-assessment and study of the situation, and then began a systematic, nationwide search for solutions to the problems of detecting, tracking, targeting, and engaging the heavy bombers. By September the General Staff had approved a defense plan outlining projected American tactics and objectives in a sustained B-52–led offensive, and the forces to be used in defending Hanoi. Over the following months, the DRVN continued to study B-52 jamming patterns, developed radar and missile engagement tactics to counter the jamming, and deployed an integrated visual and radar network to provide warning of an attack, updating its air-defense campaign plan in September and again in November. As the negotiations continued and stalemate neared in mid-December, the DRVN evacuated the nonessential population from major cities.
Nixon’s decision to send the B-52s against Hanoi triggered detailed planning and preparation throughout the US military. Target lists for the attacks were developed by the JCS and White House; detailed mission planning was conducted at the Strategic Air Command (SAC) headquarters at Offutt Air Force Base, Nebraska. Attacks by B-52s stationed on Anderson Air Base (Guam) and U Tapao Air Base (Thailand) would be supported by 7th Air Force fighters, by Task Force 77 naval forces operating off Indochina, and by air-refueling aircraft stationed on Okinawa and in the Philippines. The B-52s would conduct night attacks to counter North Vietnamese fighter defenses; 7th Air Force and TF 77 fighter-bombers would conduct day attacks to maintain the pressure on PAVN defenses and to wear down both the air defenders and the populace.
The bombers struck on the night of December 18, 1972. It was the first night of an air campaign formally designated “Operation Linebacker II” and informally remembered as the “Christmas Bombing.” SAC planners, operating from a long history of rigid centralized control, constructed an attack plan consisting of three waves of attacks, hours apart, all following the same ground track and flying at the same altitudes and airspeeds. Overall, 129 bombers attacked the Hanoi area, waves arriving throughout the night. North Vietnamese SA-2 missiles brought down three B-52s during the attack.
The second night of the offensive saw the same pattern of stereotyped, predictable, and repetitive tactics, though all the bombers made it back safely. The third night, however, proved catastrophic for the attacking bombers. Six were destroyed, with another damaged beyond repair. Concerns that had existed since the first raid now reached the highest levels, both civilian and military. The stereotyped tactics violated every principle of warfare, providing stark evidence of a command and planning system that had no feel for the existing conditions on the battlefield. The protracted cycles of planning and mission preparation prevented the lessons learned from being applied for days, trapping the air offensive in an ineffective series of highly predictable attacks. Two more bombers were destroyed the next night, December 21–2, in a raid against Hải Phòng. There were no bombers lost the next two nights, as the missions struck targets outside the concentrated defenses of the Hanoi–Hải Phòng area.
Christmas Day brought a bombing halt ordered by the White House. It was a welcome respite for both sides. For the US forces, it provided the aircrews and maintenance forces an opportunity to restructure air operations, to adjust tactical planning responsibilities and processes, and repair and service their hard-used aircraft. The North Vietnamese air-defense crews likewise took full advantage of the pause in the fighting. Despite their exhaustive preparation for the air offensive, North Vietnam’s air-defense forces had proved deficient in two respects: the density of the defenses covering Hanoi, and the number of missiles ready for use. The pause enabled them to redeploy and reposition missile batteries, and build up an inventory of missiles ready for combat. The US bombers returned to Hanoi and Hải Phòng with a massive single-wave attack on December 26, losing 2 of the 120 bombers engaged in the attack. The bombers continued with the single-wave attacks for three more nights, losing two more aircraft. The campaign closed with raids conducted on the night of December 29, with Nixon then restricting attacks on North Vietnam to 20 degrees north in response to an agreement with North Vietnam to resume negotiations.Footnote 21
The United States and North Vietnam had continued to communicate throughout the bombing, and agreed on December 28 to resume negotiations “based on the principles of the October draft embodying the textual changes agreed upon during the meetings in November and December.” This agreement constituted a diplomatic victory for the North Vietnamese side, confirming that while North Vietnam would agree to some adjustment to the terms agreed earlier, the primary issues addressed in the October agreement would remain untouched. The massive bombardment ordered by Nixon had been sufficient to meet his diplomatic and political requirements, but did not provide the basis for any significant change in the settlement. As Kissinger aide John Negroponte famously remarked, the United States had bombed North Vietnam in order to “force them to accept our concessions.” South Vietnam’s President Thiệu continued to resist the peace settlement until the final days of January, finally accepting the settlement on January 23. The agreement was signed in Paris on January 27, 1973.
Conclusion
The bitter combat of Linebacker II and its outcome reflected the conflicting strengths of the combatants. The United States brought to bear unmatchable firepower and technology, propelled by Nixon’s sense of urgency. The North Vietnamese countered these qualities through national mobilization, careful study and preparation for the campaign, and their ability to adapt rapidly to the circumstances of the air battles as they occurred.
In the end, the escalatory cycle begun by the North Vietnamese offensive, then countered by Nixon with massive reinforcements, the mining of North Vietnamese ports, and the Linebacker air campaigns, led to a bloody stalemate. Neither side proved able to establish military dominance sufficient to dictate the terms of peace. The Paris Peace Accords signed on January 27, 1973 reflected that stalemate. The United States recovered its POWs and withdrew from the war; the North Vietnamese secured their position in South Vietnam and the withdrawal of their most formidable foe, but failed to achieve the political outcome that had been the whole point of the war.
In the aftermath of the settlement, the North and South Vietnamese never suspended the conflict, with both sides aggressively violating the ceasefire. In early March 1973, Nixon considered ordering retaliatory air attacks on the North Vietnamese, but he turned against the idea. Over the following months, the North Vietnamese extended and upgraded their logistics network, rebuilt the forces that had taken so severe a beating during the Easter Offensive, and reorganized to address the operational shortfalls that PAVN forces had demonstrated during the 1972 campaign. These measures, combined with the decline of US financial and military support in the aftermath of the ceasefire, enabled North Vietnamese forces to overrun South Vietnam in a lightning offensive in March–April 1975.
