The Gulf of Tonkin Incident was an alleged pair of attacks by naval forces of the Democratic Republic of Vietnam (commonly referred to as North Vietnam) against two American destroyers, the USS Maddox and the USS Turner Joy. The attacks were alleged to have occurred on 2 August and 4 August 1964 in the Gulf of Tonkin.
Later research, including a report released in 2005 by the National Security Agency, indicated that the second attack most likely did not occur, but also attempted to dispel the long-standing assumption that members of the administration of President Lyndon B. Johnson had knowingly lied about the nature of the incident.[1]
The outcome of the incident was the passage by Congress of the Southeast Asia Resolution (better known as the Gulf of Tonkin Resolution), which granted Johnson the authority to assist any Southeast Asian country whose government was considered to be jeopardized by "communist aggression". The resolution served as Johnson's legal justification for escalating American involvement in the Vietnam Conflict.

Background
Daniel Ellsberg, who was on duty in the Pentagon that night receiving messages from the ship, reports that the ships were on a secret mission (codenamed Desoto) near North Vietnamese territorial waters. On 31 July 1964, the American destroyer USS Maddox (DD-731) began an electronic intelligence collection mission in the Gulf of Tonkin. Admiral George Stephen Morrison was in command of the local fleet from his flagship USS Bon Homme Richard (CVA-31). The ship was under orders not to approach closer than eight miles (13 km) from the North's coast and four miles (6 km) from Hon Nieu island.

First Attack
On 4 August, another Desoto patrol on the North Vietnam coast was launched by Maddox and the Turner Joy, led by Captain John J. Herrick. This time their orders indicated that the ships were to close no more than 11 miles (18 km) from the coast of North Vietnam.
In 1981, Herrick and journalist Robert Scheer re-examined Herrick's ship's log and determined that the first 4 August torpedo report which Herrick had maintained had occurred -- the "apparent ambush" -- was in fact unfounded (Ellsberg 10).
Although information obtained well after the fact supported Turner Joy Captain Herrick's statements about the inaccuracy of the later torpedo reports as well as the 1981 Herrick/Scheer conclusion about the inaccuracy of the first, indicating that there was no North Vietnamese attack that night, at the time U.S. authorities and all of the Maddox crew said they were convinced that an attack had taken place. As a result, planes from the carriers Ticonderoga and Constellation were sent to hit North Vietnamese torpedo boat bases and fuel facilities (Operation Pierce Arrow).

Alleged Second Attack
There are differing views about whether the 2 August incident was provoked by the U.S. One view is that the actions of the Maddox were provocative to the North Vietnamese because they coincided with the covert South Vietnamese raids. Since the Desoto patrols were conducted in order to gather just the sort of electronic emissions that the SOG 34A raids would provoke, it was a reasonable assumption that the two were "piggybacked." The destroyer's presence also may have been mistaken by the North Vietnamese as a sign that it was also involved directly in the raids.
Others, such as Admiral Sharp, maintained that U.S. actions did not provoke the confirmed 2 August attack. He claimed that DRV radar had tracked Maddox along the coast, thus being aware that the destroyer had not actually attacked North Vietnam. Yet they ordered their patrol boats to engage it anyway. He also noted that orders given to Maddox to stay eight miles (13 km) off the DRV coast put the ship in international waters, as North Vietnam claimed only a five-mile (8 km) nautical limit as its territory. In addition, many nations had previously carried out similar missions all over the world, and the USS John R. Craig had earlier conducted an intelligence-gathering mission in similar circumstances without incident.

Differing views of the Incident
On 4 August 1964, squadron commander James Stockdale was one of the U.S. pilots flying overhead during the second alleged attack; unlike the first attack, this one was believed to have been a false alarm. In the early 1990s, he recounted: "[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… There was nothing there but black water and American fire power." Stockdale said his superiors ordered him to keep quiet about this. After he was captured, this knowledge became a heavy burden. He later said he was concerned that his captors would eventually force him to reveal what he knew about this terrible secret.
In 1995, retired Vietnamese General Vo Nguyen Giap, meeting with former Secretary of Defense Robert S. McNamara, categorically denied that Vietnamese gunboats had attacked American destroyers on 4 August, while admitting to the attack on 2 August.
Reviewing the NSA's archives, Mr. Hanyok concluded that the NSA had initially misinterpreted North Vietnamese intercepts so as to make it appear there was an attack on 4 August. Midlevel NSA officials almost immediately discovered the error, he concluded, but covered it up by altering documents, so as to make it appear the second attack had happened. Robert McNamara, said in October 2005 that he believed intelligence reports regarding the Gulf of Tonkin incident were decisive to the war's expansion.
On 30 November 2005, the NSA released the first installment of previously classified information regarding the Gulf of Tonkin incident, including Mr. Hanyok's article, "Skunks, Bogies, Silent Hounds, and the Flying Fish: The Gulf of Tonkin Mystery, 2–4 August 1964" Cryptologic Quarterly, Winter 2000/Spring 2001 Edition, Vol. 19, No. 4 / Vol. 20, No. 1.
The Hanyok article stated that intelligence information was presented to the Johnson administration "in such a manner as to preclude responsible decisionmakers in the Johnson administration from having the complete and objective narrative of events." Instead, "only information that supported the claim that the communists had attacked the two destroyers was given to Johnson administration officials."

Later statements

Main article: Gulf of Tonkin Resolution Southeast Asia Resolution
The "Gulf of Tonkin Incident" defined the beginning of large-scale involvement of U.S. armed forces in Vietnam. Historians have shown that the second incident was, at its best interpretation, an overreaction of eager naval forces, or at its worst, a crafted pretext for making overt the American covert involvement in Vietnam.
Vietnam's Navy Anniversary Day is August 5, the date of the second attack, Vietnamese time, where "one of our torpedo squadrons chased the U.S.S. Maddox from our coastal waters, our first victory over the U.S. Navy".

See also