The Gulf of Tonkin Incident

What the claim says

The popular version of the Gulf of Tonkin story runs like this: in August 1964 American destroyers reported a second attack by North Vietnamese torpedo boats, President Lyndon Johnson used it to win a blank check from Congress, and the attack never happened, so the Vietnam War was built on a lie. Two parts of that sentence are firmly documented. The reported attack of 4 August 1964 did not take place, and the Johnson administration presented it to Congress and the public as established fact while its own records showed doubt. The third part, that the incident was deliberately invented in order to start a war, is where the documents stop. The analysts and historians who established that nothing happened on 4 August describe a mistake that was then handled selectively, not a staged event.

It helps to keep the two incidents apart. On 2 August 1964 the destroyer USS Maddox was attacked in daylight by three North Vietnamese torpedo boats; that engagement was real, and both sides agree it happened. On the night of 4 August the Maddox and a second destroyer, USS C. Turner Joy, reported a second attack in darkness and bad weather. That is the one that did not happen.

Background: covert raids and an intelligence patrol

By the summer of 1964 the United States was running two programs along the North Vietnamese coast. The first, OPLAN 34A, was a Defense Department campaign of covert raids. The NSA historian Robert Hanyok describes it as "a program of selective intrusions and attacks of graduated intensity", carried out mostly by South Vietnamese special forces with some foreign crews, with American planning, training and logistics, and he notes that no Americans were allowed to take part in the raids themselves. John Prados, who edited the National Security Archive's Tonkin briefing book, writes that Johnson approved the program in January 1964.

The second program was the DeSoto patrol: a US Navy destroyer carrying a van of Naval Security Group specialists to intercept North Vietnamese communications and radar signals. Hanyok writes that the patrols' purpose included an effort to "stimulate and record" North Vietnamese reactions. He found "no direct operational connection" between the patrols and the raids, which were managed by separate officers, adding: "At least that was the understanding back in Washington."

The timing nonetheless mattered. South Vietnamese commandos struck the islands of Hon Me and Hon Ngu in the early hours of 31 July, and Prados notes that the Maddox then approached those same islands before the 2 August clash. The Pentagon's internal history of the period concluded that the 2 August attack was "almost certainly" a case of "mistaken judgment on the part of the local Vietnamese commander", who probably associated the destroyer with the raiding force.

2 August: the engagement that did happen

On the afternoon of 2 August the Maddox was approached by three North Vietnamese P-4 torpedo boats. Hanyok's reconstruction of the intercepts has the boats leaving Hon Me at about 1300 local time, the destroyer speeding up after signals intelligence warned of an attack, and the Maddox firing three warning rounds at about 1505. Hanyok adds that the Johnson administration never reported that first salvo and insisted the Vietnamese had fired first; he calls McNamara's claim to that effect incorrect. Aircraft from the carrier USS Ticonderoga joined in within about fifteen minutes. The Maddox was unscathed apart from a single machine-gun bullet hole, and all three boats limped back to base, one with four dead and six wounded.

Prados reports that General Vo Nguyen Giap and other Vietnamese officials told a 1997 conference that the 2 August response was ordered by a local naval command, not by the leadership in Hanoi. Washington reacted cautiously: Hanyok records that Johnson wanted the event downplayed while a stern protest note was sent to Hanoi, and the president approved the reinforcement of the Maddox by the Turner Joy.

The night of 4 August

With both destroyers sailing back up the Gulf, Washington was already primed. In a telephone call at 9:43 a.m. Washington time on 4 August, before any attack had been reported, McNamara told Johnson that the destroyer was "allegedly to be attacked tonight". Prados's commentary on the tape reads this as showing that Washington was acting on radio intercepts mistakenly attributed to 4 August, and that the two men were already discussing retaliation for an attack that had not yet occurred.

On the night itself the picture on the destroyers was chaotic. Hanyok describes radar returns that flashed on and off and a Turner Joy firing more than 300 rounds at supposed boats. He says the sonar reports of torpedoes were later traced to the ships' own rudders and propellers during high-speed maneuvers. Within about an hour of the end of the action, the on-scene commander, Captain John Herrick, signaled that the "ENTIRE ACTION LEAVES MANY DOUBTS EXCEPT FOR APPARENT ATTEMPTED AMBUSH AT BEGINNING". Pilots from the Ticonderoga, circling overhead, saw nothing.

The decisive finding comes from the other side. Hanyok concludes that on 4 August "Hanoi's navy was engaged in nothing that night but the salvage of two of the boats damaged on 2 August." Giap told McNamara the same in person in 1995.

Washington decides

The doubts reached Washington within hours, and they did not stop the response. In a recorded call that The Fog of War reproduces, Admiral Ulysses S. Grant Sharp, the Pacific commander, told Lt. Gen. David Burchinal of the Joint Chiefs' staff that many of the reported torpedo contacts "appear doubtful". Relaying the on-scene view, Sharp said: "Freak weather effects on radar and overeager sonar men may have accounted for many reports." Prados records that Herrick's message reached Washington at about 1:27 p.m., during a lunch at which, according to a Pentagon chronology, Johnson agreed to a retaliatory strike, and that it "had no effect on the actions of Washington officials". McNamara later recalled that "finally late in the day, Admiral Sharp said, 'Yes, we're certain it happened.'"

What tipped the balance was signals intelligence. Hanyok reports that the Defense Secretary, the Joint Chiefs and the president treated an NSA translation of a supposed North Vietnamese after-action report as the "smoking gun" that justified air strikes. That translation, he found, had combined two separate messages about separate incidents into one. McNamara had told the Pacific command that no retaliation should occur until officials were "damned sure that the attacks had taken place", according to the Pentagon's internal history.

At the National Security Council meeting that evening, the director of the US Information Agency, Carl Rowan, asked: "Do we know for a fact that the North Vietnamese provocation took place? Can we nail down exactly what happened? We must be prepared to be accused of fabricating the incident." McNamara answered: "We will know definitely in the morning. As of now, only highly classified information nails down the incident." Johnson announced the retaliatory strikes late that night, at 11:36 p.m. by the National Security Archive's account. The raids, code-named Pierce Arrow, hit North Vietnamese naval installations on 5 August Gulf time, and Johnson's message to Congress reported that two US aircraft had been lost.

At a White House staff meeting at 8 a.m. on 5 August, a memorandum for the record shows National Security Adviser McGeorge Bundy telling staff: "On the second one the amount of evidence we have today is less than we had yesterday." The memorandum goes on to record that "This much seemed certain: There was an attack." In Bundy's account, an attack "seemed certain" while the details, how many boats were involved and how many torpedoes were fired, were "still somewhat uncertain". It also records that Bundy, answering a staff member's question about the need for a resolution, "welcomed the recent events as justification for a resolution the Administration had wanted for some time."

The resolution

On 5 August Johnson told Congress that North Vietnam had "conducted further deliberate attacks against U.S. naval vessels operating in international waters" and asked for a resolution. At a joint hearing of two Senate committees on 6 August, McNamara said: "Our Navy played absolutely no part in, was not associated with, was not aware of, any South Vietnamese actions, if there were any." Prados calls such assurances "highly misleading", noting that the raids were run with boats procured by the US Navy, targets selected by the CIA and US money, and the historian Edwin Moïse's bibliography says McNamara gave "a very inaccurate version of the incidents". On a recorded call on 3 August, McNamara had told Johnson there was "no question" the covert operations "had bearing on" the incident, and that the destroyer's presence a day after the raids "undoubtedly led them to connect the two events".

The joint resolution passed both chambers on 7 August: the House voted 416 to 0 and the Senate 88 to 2, with Wayne Morse and Ernest Gruening the only dissenters. Johnson signed it on 10 August. Its preamble stated that North Vietnamese units "have deliberately and repeatedly attacked United States naval vessels lawfully present in international waters". Its operative text approved "all necessary measures to repel any armed attack against the forces of the United States and to prevent further aggression", and section 2 said the United States was prepared, as the President determines, to take "all necessary steps, including the use of armed force" to assist any member or protocol state of the Southeast Asia Collective Defense Treaty requesting help.

The resolution was not conjured overnight. A State Department draft resolution on Southeast Asia dated 24 May 1964 is printed in the official Foreign Relations series, with a note that the papers prepared for that meeting were "all working papers, no official standing". Hanyok adds that William Bundy's June draft was shelved because Johnson feared it would ruin the image of moderation he was cultivating before the November election. The Pentagon's own history records that the reprisals carried out recommendations "made to the President by his principal advisers earlier that summer and subsequently placed on the shelf".

How the account came apart

Doubts surfaced early but slowly. Senator J. William Fulbright, who had introduced the resolution in the Senate, chaired a Foreign Relations Committee hearing on 20 February 1968 titled "The Gulf of Tonkin, the 1964 Incidents". McNamara, the lead witness, described the intercepts as coming from "a highly classified and unimpeachable source" and declined to leave copies with the committee. A committee staff member who was later allowed to scan them wrote that the single 4 August message he saw read to him as "a boastful summary of the attack on August 2". Hanyok adds that NSA's deputy director, Louis Tordella, was quoted in 1972 as saying the 4 August intercepts pertained to the 2 August attack.

The Pentagon Papers are often cited in this context, but they cut both ways. The Defense Department study that Daniel Ellsberg leaked in 1971, commissioned by McNamara in 1967, includes a volume on July to October 1964. It acknowledges "some momentary uncertainty about the actuality of the second attack on August 4th" while saying confirming evidence arrived before the reprisal. Its value is in documenting the pre-planning, not in exposing the incident.

Two decades later the principals began to concede the point. In his 1995 memoir McNamara wrote that the second attack "appears probable but not certain"; the paperback edition added that on 9 November 1995 General Giap told him in Hanoi that the presumed attack of 4 August did not occur. The Associated Press reported Giap's words as "On the fourth of August, there was absolutely nothing." In The Fog of War (2003) McNamara said of 4 August: "It didn't happen." He added that Johnson had authorized the bombing "in response to what he thought had been the second attack".

The fullest record came from inside the intelligence community. Hanyok's article, "Skunks, Bogies, Silent Hounds, and the Flying Fish: The Gulf of Tonkin Mystery, 2-4 August 1964", was published in the classified Cryptologic Quarterly in early 2001. The New York Times reported on 31 October 2005 on the controversy over its release; an NSA spokesman said the delay was meant to provide "a more contextual perspective", and the Associated Press reported on 1 November that the agency planned to release the article and related materials "next month". In an update dated 1 December 2005, the National Security Archive reported that the NSA had declassified more than 140 documents on the incident, including the article.

What the NSA historian found

Hanyok's two main conclusions are stated in the opening pages. First, "it is not simply that there is a different story as to what happened; it is that no attack happened that night." Second, the intelligence reaching the Johnson administration was handled so that only material supporting an attack was passed on. Nearly 90 percent of the relevant intercepts was kept out of the summary reports and the October 1964 chronology, the official account used fifteen reports against the 122 relevant products Hanyok located, and the original decrypted Vietnamese text behind the key translation has disappeared.

Hanyok is explicit about what he did not find. He says the mishandling "was not done in a manner that can be construed as conspiratorial, that is, with manufactured evidence and collusion at all levels." He found no "smoking gun" memorandum, concluded that the NSA personnel in the crisis center generally believed an attack had occurred, and rejected the idea that they were pressured by the administration. He is equally explicit that the selective reporting was deliberate: "a conscious effort ensued to demonstrate that the attack occurred", and "one can easily deduce the deliberate nature of these actions", which he calls "an active effort to make SIGINT fit the claim of what happened during the evening of 4 August". Why the NSA personnel acted as they did "will probably never be answered".

Key people and what the record shows

Johnson ordered the destroyers reinforced, approved retaliation on 4 August, addressed the nation that night, requested the resolution and signed it. None of Hanyok, Moïse or the Pentagon's own history says he knew the attack was false. The Miller Center judges that by 10 August "several senior officials—and probably the president himself—had concluded that the attack of August 4 had likely not occurred", while Prados dates Johnson's first expressed doubts to a month later. In August 1967 Johnson said the administration had not thought the resolution necessary for what it was doing.

McNamara briefed Johnson and Congress; historians describe his 1964 testimony on the provocation as misleading, and his later statements are covered above. Bundy welcomed the incident as justification for a resolution already wanted. Sharp, Herrick and the NSA analysts supplied the conflicting reports on which the decisions rested. Stockdale, who flew over the scene, later wrote that he had "the best seat in the house from which to detect boats" and saw none. Fulbright introduced the resolution and chaired the 1968 inquiry; Morse and Gruening voted against it.

Consequences

The State Department's historians say the resolution "became the legal basis for the Johnson and Nixon Administrations prosecution of the Vietnam War", and that Congress passed it assuming the president would return for support before further escalation. Johnson and his advisers ordered Operation Rolling Thunder, a sustained bombing campaign against the North, in February 1965, and the first regular ground combat deployments followed.

Congress moved to undo the resolution. On 24 June 1970 the Senate voted to rescind it; Hanyok says the initiative originated with Senator Robert Dole. The Nixon administration said it was not relying on the resolution. The repeal that became law was section 12 of Public Law 91-672, an act amending the Foreign Military Sales Act, approved on 12 January 1971; it terminated the resolution when the second session of the 91st Congress last adjourned. Repeal did not end the war: a federal appeals court held that authorization could be inferred from war appropriations, and in 1973 Congress passed the War Powers Resolution over Nixon's veto. The National Archives lists 58,220 US military fatal casualty records for the war, and Prados puts the Vietnamese death toll at several million. The resolution did not by itself cause those deaths; it was the legal basis the administrations cited for the war in which they occurred.

What remains disputed or unknown

Historians differ on intent. Moïse, who describes his 1996 book as the first study to combine American records, interviews and Vietnamese sources, concludes that "there was no attack" but that the original report "was not a lie concocted to provide an excuse for escalation; it was a genuine mistake." Prados reads the same record more darkly, as "Washington rushing to a judgment" that it seized on in support of "its predetermined intention to escalate the conflict in Vietnam". Hanyok's finding is narrower: no conspiracy with the administration, but deliberate selective reporting within the NSA.

Several things remain unknown. Why the NSA personnel handled the intercepts as they did "will probably never be answered", in Hanyok's words, and the original Vietnamese text had not been located when he wrote. How far Johnson personally doubted the second attack on 4 and 5 August is unresolved. Whether the Maddox's DeSoto mission was knowingly coordinated with the covert raids is also contested: Hanyok found separate management, while Prados argues that senior officials understood the connection.

How Tonkin is used in later arguments

Tonkin became shorthand for the idea that a government lied its country into war. Prados's August 2004 essay noted that the episode "has regularly been invoked in connection with the lead-up to the war in Iraq", and argued that the manipulation of the 1964 situation "bears considerable similarity" to the Bush administration's handling of Iraq intelligence. The Times reported that some NSA officials feared "uncomfortable comparisons with the flawed intelligence used to justify the war in Iraq" if Hanyok's article appeared. Such comparisons concern how flawed intelligence can drive a decision to use force; they do not show the two episodes were the same kind of deception.

What is documented, and where the claim outruns it

Declassified signals-intelligence histories and later official reviews show that the second reported attack was deeply doubtful and that public certainty exceeded the evidence. The 4 August attack did not happen: the NSA's own historian says so, North Vietnam's defense chief told McNamara so, and McNamara later agreed. The documents also show that the destroyers' doubts reached Washington before the retaliation was ordered, that the covert background was misdescribed to Congress, and that a resolution had been drafted before the incident and was welcomed as a justification.

The unsupported leap is treating the episode as proof that the incident was deliberately fabricated, that Johnson knowingly lied about an attack he knew had not occurred, that the whole Vietnam War was manufactured from one hoax, or that all military incidents are staged in the same way. The record that Hanyok, Moïse and the Pentagon's own history support is of a mistaken report, selectively documented by the NSA, and an administration that used it eagerly.