It neither forced any kind of diplomatic solution, nor did it sufficiently interrupt North Vietnam’s aid to the South. This essay will show how the Johnson Administration’s flawed approach to bombing in North Vietnam led to the failure of Operation Rolling Thunder. This is important because it reveals the limitations of conventional forms of warfare and highlights the importance of pursuing a strategy free of conflicting political and military goals.

The operation failed because, out of an over-riding fear of provoking the USSR and China into a confrontation, and in a gross underestimation of Hanoi’s determination, the Johnson administration insisted upon a bombing policy of gradual and limited pressure, which proved to be a backwards approach to fighting an interdiction campaign and an ineffective strategy against an externally supported and strong-willed adversary in Hanoi that simply refused to yield to bombs.

The United States’ first concerted effort at bombing North Vietnam, codenamed Operation Rolling Thunder, represented a considerable break from previous U.S. bombing policy in Vietnam. From August, 1964, until March of the following year, the U.S. had pursued a strategy of “tit for tat” measured bombing responses to specific revolutionary military action,1 hoping to send a message to the guerrillas in the south and to Hanoi that their behaviour would not be tolerated.

By February, however, the White House had decided that, in light of continued enemy pressure, these reprisal missions were not sufficient. Opinion was virtually unanimous in the Johnson administration that sustained bombing of the North was necessary. As early as January, 1965, U.S. policy-makers believed that, if South Vietnam were to be preserved, air strikes were imminently required.2

The State Department’s Aggression from the North: The Record of North Viet-Nam’s Campaign to Conquer South Viet-Nam, released the following month, called for strikes against the North as an obligatory response to Northern aggression.3 It also indicated that U.S. bombing of the North would be “the least risky and least costly option” in terms of American lives, and might also win the support of influential advocates of air power in congress.4

The National Liberation Front’s (nlf) attack on Pleiku on February 7th, which killed eight Americans, served as sufficient context for the release of President Lyndon Johnson’s February 13th Presidential Directive calling for “a program of measured and limited air action” against “selected military targets” in North Vietnam.5 More recently, the historical community has accepted the Pleiku Incident as a pretext for Rolling Thunder, and not a reason per se: Larry Addington, Professor Emeritus of History at the Citadel, wrote in 2000 that the President “needed a provocation for justifying the unloading of rolling thunder against North Vietnam” and that the attack on Pleiku served in this role.6 Regardless of motivation, however, a clear change in bombing policy was evident. The series of attacks that began on March 2nd against North Vietnam were the first strikes7 taken to pursue this new policy, “not tied to any specific action”8 by the North Vietnamese.

Advocates of Rolling Thunder hoped that it would affect the North Vietnamese war effort in two ways. First, it was designed to persuade Hanoi to cease its support for a revolution in the South and head towards a diplomatic compromise. Second, Rolling Thunder aimed to block the southward flow of supplies with a conventional interdiction campaign. However, by the close of the campaign, neither of these objectives had been met.

The key assumptions behind the campaign’s crucial political objectives in the North lay in the Johnson administration’s belief that North Vietnam was vulnerable to air power and that there had to be “some point at which the drv [Democratic Republic of Vietnam, i.e. North Vietnam] policy-makers would break.”9 National Security Advisor Walt Rostow explained that since Ho Chi Minh had an industrial complex to protect, he was “no longer, as he had been when fighting the French more than a decade earlier, a guerrilla fighter with nothing to lose.”10 However, in stark contrast to this assertion, a committee headed by one of Rostow’s own deputies concluded that economically-oriented bombing of the North would necessarily fail, because economic growth was not the regime’s priority.11 The committee insisted that bombing could not weaken such a regime, and might even strengthen it. In a serious underestimation of the North Vietnamese leadership’s desire for reunification with the South, Rostow chose to ignore this study.

Similar feats of underestimation were rampant in the Johnson administration and throughout America. Spencer Tucker, Professor of Military History at the Virginia Military Institute, observed in 1999 that throughout the course of the war American leaders “consistently underestimated the determination”12 of their North Vietnamese counterparts. Naval historian John Sherwood explained in 2004 that American policy-makers failed to understand North Vietnamese “leaders’ long time horizons and their high tolerance for losses.”13 Prominent military authors of the early Vietnam era, however, failed to grasp this. In May 1965, John Greene wrote an article in Air Force Magazine, explaining:

The experts here believe it might take another two months, perhaps more, of the selected air strikes to convince Ho Chi Minh and his communists that real ruin lies just back of yonder cloud if they do not change their ways.14

Even as this article was published, the North Vietnamese leadership was engaged in repeated public statements of an entirely opposite sentiment, maintaining that they could carry on the struggle almost indefinitely. Ho Chi Minh informed President Lyndon Johnson that, though the war might take fifteen years, eventually Vietnam would prevail.15 North Vietnamese Premier Pham Van Dong rhetorically asked Harrison Salisbury of the New York Times “How long do you Americans want to fight? One year, two years, three years, five years, ten years, twenty years,” adding that “[w]e will be glad to accommodate you.”16 Speaking to his own people, Pham Van Dong’s colourful rhetoric is even more forceful:

We have been fighting for our independence for four thousand years. We have defeated the Mongols three times. The United States … strong as it is, is not as terrifying as Genghis Khan.17

After the war, accounts from the North Vietnamese people showed these statements to be more than mere rhetoric. Huong Van Ba, a repeat-infiltrator through the Ho Chi Minh Trail, expressed “such hatred for the enemy and such devotion to the noble cause of liberating our suppressed people that we felt we could overcome any difficulty and make any sacrifice.”18 Sau Thuong, also operating along the Ho Chi Minh Trail, asserts that he “would rather have died in the mountains”19 than fail his superiors in the North. Born into a social matrix that considered self-sacrifice to be “a normal concomitant of the human condition,”2021 The Johnson administration in early 1965, however, had what Sherwood has termed “difficulty understanding Vietnamese politics and culture,”22 and thus continued to underestimate the resolve of the North Vietnamese people. people from North Vietnam were accordingly resilient and determined. Later in the war, U.S. General Ridgway would note admiringly that “they are used to all manner of deprivations which would be extreme hardship to our men.”

Faced with an enemy culture of such hardened hostility and resilience, America was, not surprisingly, unsuccessful in all of its attempts at diplomacy with the North. Secretary of Defense Robert McNamara’s policy of pausing the bombing in the hopes that Hanoi would initiate talks – something that was tried at least seven times during the more than three years of Rolling Thunder23 – never bore fruit. In fact, rather than being influenced to negotiate, Hanoi made the bombing into a propaganda issue, generating useful hatred for the Americans and rallying its citizens with calls for the bombing’s unconditional halt.24 One northern propagandist, Hoang Quoc Viet,1 wrote in the Hanoi daily paper Nhan Dan on April 21st, 1965, that:

Johnson further lied that the U.S. attacks on the drv were aimed at military targets, and not to massacre the people, that they were carefully limited. But everybody knows that the so-called military targets attacked by the United States in North Vietnam are populated areas, villages, provincial capitals, townships, schools, markets, and even churches and hospitals.25

Even if such claims were not completely true, and American bombers did not engage in operations for the sole purpose of slaughtering North Vietnamese civilians, the fact remains that the presence of American planes overhead and the sight of American bombs falling on North Vietnam served to rapidly polarize popular opinion against the Americans. Backed by solidified popular support,26 Pham Van Dong very publicly rejected any moves towards peace without the bombing’s cessation, “permanently and without conditions.”27 Even after more than two years of American pressure, Ho Chi Minh declared in 1967 that “the Vietnamese people will never submit to force… they will never accept talks under the threat of bombs.”28 Despite the fact that U.S. pilots could, and frequently did, drop more bombs in one day than the French could deliver during the entire siege of Dien Bien Phu,29 bombing never brought Hanoi to the negotiating table.

Non-public attempts at diplomacy were equally unsuccessful. In what was known as Operation Marigold, America made use of Polish diplomats in an attempt to covertly open a diplomatic channel. However, Washington’s relentless fixation on using bombing pauses as a diplomatic weapon, despite all of its previous failures, continued to cause problems in opening talks. Janusz Lewandowski, the leading Polish diplomat, explained that Hanoi would not reciprocate in any de-escalation process because it would strengthen “the governmental status quo in South Vietnam, whereas it was precisely a change in the South Vietnamese government that the Communist side required.”30 As Ho Chi Minh explained in Americanized terms, “it is like being asked by a Chicago gangster who has you at gun-point what you are willing to pay him not to shoot you.”31 Even in secret, bombing pauses were non-starters for diplomatic progress.

Increases in bombing were just as useless, clouding any remaining perception in North Vietnam that America may actually have wanted peace. After an escalation of bombing, Assistant Secretary of State William Bundy reported that “our bombing actions had left the Soviets – and by implication, Hanoi – in complete doubt as to what our intentions and views really were.”32 The very fact that bombing pauses were always followed by more bombing led to a profound lack of trust between Hanoi and Washington. American negotiators in Paris often “ran into suspicions”33 from Northern representatives that the United States would just increase the bombing again, a claim that was very hard to dispute when it had been proven time and again with recent events. It became clear to all involved that whatever was done with bombing, escalation or pause, the diplomatic situation worsened.

Rolling Thunder’s powerlessness to bring about a diplomatic response from the North was compounded by politically-driven tactical limitations on bombing operations from Washington. Key civilians in the administration, most notably McNamara,34 shied away from the abrupt and concentrated strategy of aggression advocated by the Joint Chiefs of Staff, fearing that it would provoke a wider conflict with China or the Soviet Union. After all, the world had been brought to the brink of nuclear war during the Cuban Missile Crisis only four years before, and the need to keep situations from escalating out of control was still ripe in memory.

Cornelius Sullivan’s 1968 study, published just after Rolling Thunder’s conclusion, explained that the possibility that China and the Soviet Union might “react strongly” to a concentrated, fast, and heavy bombing campaign in the North was “without doubt a compelling argument” against such action.35 This view is still widely held. In 2000, Larry Addington wrote that unlimited conventional bombing in North Vietnam would have “risk[ed] war with the People’s Republic of China, if not the Soviet Union,” and pointed to Beijing’s public warnings that it would not remain indifferent to North Vietnam’s situation.3637 Clearly, the Johnson administration felt the need to retain a degree of control over the operation. Additionally, the less discriminate bombing advocated by the Joint Chiefs would turn much world opinion against the United States.

Washington’s control over the bombing was, accordingly, very tight. In fact, as Sullivan explained in 1968, the White House had maintained “direct and immediate control over almost every aspect of the air war in the North,”38 bypassing Military Assistance Command, Vietnam (macv) entirely39. This was evident from the start of the campaign, formalized on April 27, 1965, when McNamara indicated that the President would retain control over the operation’s “tempo and scope.”40

It cannot be known if China and the Soviet Union would have responded with military force had the Joint Chief’s more aggressive plan been implemented. What can be analysed without much speculation, however, are the direct effects of Washington’s policy on Rolling Thunder’s effectiveness. Johnson and McNamara imposed a policy of steady escalation on the strikes,41 so severely limiting the targets that could be hit at the start of the operation that that Maxwell Taylor, former Chairman of the Joint Chiefs of Staff and ambassador to South Vietnam at the time, exclaimed early on “I fear that to date Rolling Thunder in their eyes has merely been a few isolated thunderclaps.” 42 At the onset of the operation, days – sometimes weeks – would elapse between strikes. Throughout 1965, the government in Hanoi was still more under threat of pressure than it was under any real stress, and certainly not in any environment likely to force its diplomatic hand.

Washington limited the targets for Rolling Thunder geographically as well, to be broadened only exceedingly slowly. Indeed, Johnson boasted that he wouldn’t “let those Air Force generals bomb the smallest outhouse … without checking with me.”43 Air Force historian John Correll wrote that, at the start of the campaign, North Vietnam’s real strength around Haiphong and Hanoi was “not touched, not even threatened… a strange way to begin a war.”44 For a period of months, all authorized targets were below the 19th parallel. The bomb line then was extended northward to targets below the 20th parallel, and, by mid-1966, into the Red River Delta.45 In July 1967, 169 out of 436 “Primary Target Systems” in North Vietnam were still “Not Authorized” for attack.46 Only by August 1967 were American aircraft authorized to attack targets near Hanoi and Haiphong.47 By this time, the North Vietnamese knew what to expect, and understood how to deal with air attack.

Thus, not only was this incremental pressure ineffective in its diplomacy-inducing aims, it also gave the North Vietnamese time to adapt to the bombing. Attacks on North Vietnamese petroleum, oil, and lubricants came too late to have a decisive effect because the North Vietnamese had been able to disperse a significant portion of its supplies and had developed underground storage facilities.48 Over Rolling Thunder”s three-year course, North Vietnam developed “a comprehensive system” to repair damaged communication lines and keep them open, coordinating the efforts of more than half a million men.4950 and had perfected them by the time American strikes became more threatening. For the first two years of the campaign, U.S. pilots were forbidden to strike the MiG bases from which enemy fighters were launched,51 allowing the North Vietnamese Air Force to operate without harassment and control the tempo of its action to conserve its losses. Washington’s gradual escalation policy thus made U.S. pilots’ jobs exponentially more difficult, and vastly reduced the effectiveness of their strikes. Anti-aircraft gunners, radar technicians, and surface-to-air missile (sam) operators had time to familiarize themselves with their newly-imported Soviet and Chinese weapons and equipment. During Rolling Thunder’s early stage, North Vietnamese gunners developed innovative defensive tactics, such as frequently relocating sam sites to retain the element of surprise,

Even when most of North Vietnam was within the bomb line, Johnson and McNamara still managed to hinder the effectiveness of their strikes. Because it authorized only a small number of targets for strike during any one period, Washington effectively killed the element of surprise in its attacks.52 Known targets were heavily defended, forcing the United States to pay “a high price in men and equipment”53 whenever it ventured to strike. Not only were targets controlled, but so too was the mode of attack. Lieutenant General Joseph Moore, commander of the 2nd Air Division and its successor organization, the 7th Air Force, wrote:

I was never allowed in the early days to send a single airplane north [without being] told how many bombs I would have on it, how many airplanes were in the flight, and what time it would be over the target.54

Washington even dictated flight paths of strike aircraft and even the types of ordnance they were permitted to employ,55 leaving no room for military personnel to take even the most basic military decisions. The time of attack on a target in North Vietnam was usually the same as that for the previous strike, so that North Vietnamese defence crews were on alert when the strike came.56 Washington, in a serious misunderstanding and underestimation of the capability of North Vietnamese air defence,57 capped the number of aircraft dedicated to flak and sam suppression at “woefully low” levels.58 Pilots were generally ordered not to attack sam sites unless directly fired upon.59 In one extreme example of the absurdity of this policy, when Navy pilots discovered 111 sams loaded on railcars near Hanoi, they were denied permission to bomb them. In exasperation, one of these pilots exclaimed: “We had to fight all 111 of them one at a time.”60 The White House imposed its no-strike sam policy because its obsession with diplomatic manoeuvring distorted its view of the military reality of the situation. Assistant Secretary of Defense John McNaughton wrote in a memo to McNamara “We won’t bomb the [sam] sites, and that will be a signal to North Vietnam not to use them.”61 In 2004, Sherwood wrote that politically-driven interference in military matters led to severe planning shortcomings that were directly responsible for making Rolling Thunder “one of the most costly air campaigns in history,” and seriously reduced the effectiveness of air strikes on North Vietnam.62

Unwilling to apply maximal effort to its strikes, the United States failed not only in its diplomatic-political objectives against the North but also in its interdiction campaign. Sherwood wrote that North Vietnam “exploited U.S. bombing restrictions at every turn.”6364 Instead, the U.S. civilian leadership insisted upon strikes only after supplies had been dispersed. Though over 10,000 North Vietnamese trucks were eventually destroyed during Rolling Thunder, the North Vietnamese were actually able to increase the southward flow of supplies throughout the bombing campaign.65 During peak periods, an estimated 10,000 tons66 of war materiel per week was “trucked, biked, boated, and carried down the [Ho Chi Minh] Trail”67 to aid the nlf. Personnel infiltration increased similarly, even as Rolling Thunder intensified, from about 35,000 men in 1965 to as many as 90,000 in 1967.68 McNamara would later tell the Senate Armed Services and Appropriations Committees, With attacks rarely authorized against major ports and staging areas – essential areas for the success of an interdiction campaign – America failed to destroy North Vietnam’s supplies at their source.

I don’t believe that the bombing up to the present has significantly reduced, nor any bombing that I could contemplate in the future would significantly reduce, the actual flow of men and materiel to the South.69

North Vietnam’s ability to sustain its war effort and continue to provide supplies to the South hinged directly upon its support from China and the Soviet Union, a factor that Johnson was constantly aware of but, understandably, unwilling to deal with militarily. However, before 1965, Russian and Chinese military assistance to North Vietnam was relatively insignificant, and no official pledge had been made. It was Johnson’s own actions against the North that secured forthcoming support for Hanoi.

When Washington’s retaliatory attacks following the February 1965 Pleiku incident coincided with Soviet Premier Alexei Kosygin’s visit to Hanoi, the Russians pledged substantial military and economic assistance.70 Within several weeks, the first sams were arriving in Haiphong.71 By the end of 1965, North Vietnam would have received 60 of these advanced missile launching platforms, and would boast more than 250 by the end of 1967.72 Soviet history expert I.V. Giaduk wrote that:

The Pleiku incident and U.S. retaliation destroyed what was left of Moscow’s hope to avoid internationalization of the conflict in Vietnam. As a result the Soviet Union was forced to set aside its policy of propaganda and noninvolvement and plunge into a war with unpredictable consequences.73

When the Chinese followed suit, it was clear that Johnson’s bombing of the North had – despite his grave fears – fully internationalized the war, increasing the political dangers of escalation and the immediate threats to U.S. pilots. Although when Rolling Thunder began the North Vietnamese air defence system had no jet aircraft, no missiles, fewer than 20 radar installations, and a mere handful of anti-aircraft guns, within two years support from the U.S.S.R. gave North Vietnam what Tucker has called “the most sophisticated air defence system in the world.”74 On any given month in 1967, the North Vietnamese used their 10,000 anti-aircraft guns to fire more than 25,000 tons of flak at American planes, and launched hundreds of missiles from more than 25 sam battalions.75 By the end of this year, the North Vietnamese Air Force possessed 80 operational MiG fighters, including the most recent MiG-21.76 Worrying statistics of this magnitude were clearly available at the time. Sullivan wrote in 1968 that Northern air defence was “one of the most intensive systems yet devised,” more concentrated than anything U.S. pilots faced during the Second World War over Germany.77

This Soviet and Chinese military support was put to deadly use. From 2 March 1965 to 31 October 1968, the duration of Rolling Thunder, 922 U.S. planes were lost over North Vietnam.78 Such losses were disproportionately high compared with losses over the South. In 1966, for example, though only 30% of American sorties were flown over the North, 60% of U.S. losses were incurred there.79 A report in May 1967 from the Office of the Secretary of Defense stated that the air campaign against “heavily defended areas” cost the United States one pilot in every 40 sorties.80 Given that a tour of duty in Vietnam could last for 200 missions,81 the long-term odds were stacked against U.S. strike pilots. Clearly, Soviet and Chinese military support was instrumental in North Vietnam’s ability to defend itself and hurt the Americans.

The North Vietnamese resistance effort, however reliant on external support, was nonetheless ultimately determined by its own citizens and leadership. The country was able to capitalize on its low-tech advantages over the United States in order to counter American technological dominance. To counter U.S. high explosives in the form of air-dropped mines or direct air attack, villagers found suspicious objects and poked them with long sticks from behind bamboo shields; they dragged logs and chains to set off mines and foul sensors; they created false truck convoys with fake headlights; and they constructed dummy supply dumps and bridges.82

Camouflage was raised to an art.83 To aggravate the U.S. further, the geography of the area was such that it made movement almost impossible for aircraft to control.84 As Sullivan reported, this situation was worsened by North Vietnam’s “primitive”85 transportation system. Earl Tilford, published in Armed Forces and Society, emphasized the uselessness of American technological superiority in the face of North Vietnam’s sound strategy of resistance.

Cluster bombs, napalm, herbicide defoliants, sensors dropped along the Ho Chi Minh Trail to monitor traffic and aid in targeting, gunships, and electro-optically guided and laser-guided bombs all promised much, and while some delivered a great deal of destruction, in the end technologically sophisticated weapons proved no substitute for strategy.86

North Vietnam simply did not require technological superiority to resist effectively. In fact, its technological inferiority to America actually proved to be an advantage. Though it lost 65% of its oil supplies, Hanoi was not phased; this had little effect upon a nation whose primary source of farming energy was the water buffalo, and whose primary mode of transportation was the bicycle.87 America’s bombing campaign, even at its height, failed to hurt North Vietnam’s agricultural economy enough to impede its war effort, or even to elicit a political response. Harry Ashmore and William Baggs, American newspaper editors in North Vietnam attempting to initiate peace talks in 1967, noted that the bombing of the North simply “had not disrupted the economy of the mostly agricultural country.”88 McNamara, by this time fully disillusioned as to bombing’s real effectiveness, agreed.89 Rolling Thunder, as it was executed, was simply unable to bring the North Vietnamese agricultural economy to a standstill.

In addition to its ineffectiveness against the North, Operation Rolling Thunder made America’s military situation in South Vietnam much more vulnerable. The first U.S. ground forces in Vietnam were deployed to Da Nang on March 8, 1965, to defend its air base.9091 A direct line can be drawn from this first ground involvement to the North Vietnamese and nlf’s Tet Offensive, which destroyed the U.S. military’s hopes for a short war and broadened and deepened American public opinion against U.S. involvement in Vietnam. Rolling Thunder, along with the rest of America’s military involvement in Vietnam, soon fell victim to the negative publicity generated by Tet.92

After this disastrous campaign, in which almost 4,000 Americans were killed, Johnson exclaimed on March 28 1968 that “everybody is recommending surrender.”93 In a nationally broadcast speech three days later, he announced (along with his own resignation from the next election campaign) a partial bombing halt that would stop U.S. attacks over North Vietnam.94 By November 1968, just before the U.S. election, all bombing of North Vietnam ceased.95 McNamara later explained that in this way Rolling Thunder “not only started the air war but unexpectedly triggered the introduction of U.S. troops into ground combat as well.”

Thus, Operation Rolling Thunder ended in terrible disappointment for the Johnson Administration. It was a failure on massive terms. Severely limited and controlled by the Communist-fearing civilian administration in Washington, and hampered by a gross underestimation of North Vietnam’s human capability to resist, the campaign was doomed from its onset. Though North Vietnamese 52,000 civilians died as a result of Rolling Thunder,96 Hanoi remained resolute. In the end, nothing – neither military nor political gains – could be shown for America’s losses in the air.