On the evening of 4 August, the ships opened fire on radar returns that had been preceded by communications intercepts, which US forces claimed meant an attack was imminent.

[14][15] The outcome of the incident was the passage by U.S. Congress of the Gulf of Tonkin Resolution, which granted U.S. President Lyndon B. Johnson the authority to assist any Southeast Asian country whose government was considered to be jeopardized by communist aggression.

After Kennedy's assassination, Johnson ordered in more U.S. forces to support the Saigon government, beginning a protracted United States presence in Southeast Asia.

[25] Although the boats were crewed by South Vietnamese naval personnel, approval for each mission conducted under the plan came directly from Admiral U.S. Grant Sharp Jr., CINCPAC in Honolulu, who received his orders from the White House.

[26] After the coastal attacks began, Hanoi, the capital of North Vietnam, lodged a complaint with the International Control Commission (ICC), which had been established in 1954 to oversee the terms of the Geneva Accords, but the U.S. denied any involvement.

[citation needed] In 1962, the U.S. Navy began an electronic warfare support measures (intelligence gathering) program, conducted by destroyer patrols in the western Pacific, with the cover name DESOTO.

[27] Daniel Ellsberg, who was on duty in the Pentagon the night of 4 August, receiving messages from USS Maddox, reported that she was on a DESOTO mission near Northern Vietnamese territorial waters.

[5] In this context, on July 31, Maddox began patrols of the North Vietnamese coast to collect intelligence, coming within a few miles of Hòn Mê island.

[30] Four USN F-8 Crusader jets launched from Ticonderoga and 15 minutes after Maddox had fired her initial warning shots, attacked the retiring P-4s,[5] claiming one was sunk and one heavily damaged.

The original account from the Pentagon Papers has been revised in light of a 2001 internal NSA historical study, which states:[5]At 1500G, Captain Herrick (commander of Maddox) ordered Ogier's gun crews to open fire if the boats approached within ten thousand yards.

[34][35] The North Vietnamese stance is that they always considered a 12 nautical mile limit, consistent with the positions regarding the law of the sea of both the Soviet Union and China, their main allies.

Despite the Navy's claim that two attacking torpedo boats had been sunk, there was no wreckage, bodies of dead North Vietnamese sailors, or other physical evidence present at the scene of the alleged engagement.

I think it is now clear [the second attack] did not occur ... One hour later, Herrick sent another cable, stating, "Entire action leaves many doubts except for apparent ambush at beginning.

"[38] In response to requests for confirmation, at around 16:00 Washington time, Herrick cabled, "Details of action present a confusing picture although certain that the original ambush was bona fide.

[5] Shortly before midnight, on 4 August, Johnson interrupted national television to make an announcement in which he described an attack by North Vietnamese vessels on two U.S. Navy warships, Maddox and Turner Joy, and requested authority to undertake a military response.

[40][41] Johnson's speech repeated the theme that "dramatized Hanoi/Hồ Chí Minh as the aggressor and which put the United States into a more acceptable defensive posture.

"A close scrutiny of Johnson's public statements ... reveals no mention of preparations for overt warfare and no indication of the nature and extent of covert land and air measures that already were operational."

Early on 5 August, Johnson publicly ordered retaliatory measures stating, "The determination of all Americans to carry out our full commitment to the people and to the government of South Vietnam will be redoubled by this outrage."

"[52] According to Ray McGovern, CIA analyst from 1963 to 1990, the CIA, "not to mention President Lyndon Johnson, Defense Secretary Robert McNamara and National Security Adviser McGeorge Bundy all knew full well that the evidence of any armed attack [...] was highly dubious.... During the summer of 1964, President Johnson and the Joint Chiefs of Staff were eager to widen the war in Vietnam.

[51] By early afternoon of 4 August, Washington time, Herrick had reported to the Commander in Chief Pacific in Honolulu that "freak weather effects" on the ship's radar had made such an attack questionable.

But he did not immediately call Johnson to tell him that the whole premise of his decision at lunch to approve McNamara's recommendation for retaliatory air strikes against North Vietnam was highly questionable.

He asserts "I maintain that President Johnson, Secretary McNamara and the Joint Chiefs of Staff gave false information to Congress in their report about US destroyers being attacked in the Gulf of Tonkin.

As a result, planes from the aircraft carriers Ticonderoga and Constellation were sent to hit North Vietnamese torpedo boat bases and fuel facilities during Operation Pierce Arrow.

Stockdale writes in his 1984 book Love and War: "[I] had the best seat in the house to watch that event, and our destroyers were just shooting at phantom targets—there were no PT boats there ...

[14][15] A taped conversation of a meeting several weeks after passage of the Gulf of Tonkin Resolution was released in 2001, revealing that McNamara expressed doubts to Johnson that the attack had even occurred.

[63] In the fall of 1999, retired Senior CIA Engineering Executive S. Eugene Poteat wrote that he was asked in early August 1964 to determine if the radar operator's report showed a real torpedo boat attack or an imagined one.

Schaperjahn confirmed White's assertions that Maddox's sonar reports were faulty and the Johnson administration knew it prior to going to Congress to request support for the Gulf of Tonkin Resolution.

[68] Reviewing the NSA's archives, Hanyok concluded that the 4 August incident began at Phu Bai Combat Base, where intelligence analysts mistakenly believed the destroyers would soon be attacked.

[67]: 48–49 On 30 November 2005, the NSA released a first installment of previously classified information regarding the Gulf of Tonkin incident, including a moderately sanitized version of Hanyok's article.

Faced with this attitude, Ray Cline was quoted as saying "... we knew it was bum dope that we were getting from Seventh Fleet, but we were told only to give facts with no elaboration on the nature of the evidence.