Short answers, pulled from the story.
No. The 4th of August 1964 attack was never real. Declassified NSA documents, the 2005 Hanyok study, and admissions by former Secretary of Defense Robert McNamara and former North Vietnamese General Võ Nguyên Giáp all confirmed that no North Vietnamese vessels were present that night. The 2nd of August engagement was real; the 4th of August one was not.
Congress passed the Gulf of Tonkin Resolution, formally H.J. RES 1145 and titled the Southeast Asia Resolution, on the 7th of August 1964. It authorized President Lyndon B. Johnson to take all necessary steps, including the use of armed force, to assist any Southeast Asian state whose government was threatened by communist aggression. Johnson used it as the legal basis for deploying conventional U.S. forces to South Vietnam and for commencing open warfare against North Vietnam in early 1965.
Hanyok concluded that NSA staff deliberately skewed intelligence reports to create the impression that an attack on U.S. destroyers had occurred on the 4th of August 1964. His findings were first published in the Winter 2000/Spring 2001 edition of Cryptologic Quarterly. The NSA released a sanitized version of his study on the 30th of November 2005, and a broader NSA history including his chapter was released in January 2008.
Operation Plan 34-Alpha was a highly classified U.S. covert action program against North Vietnam that began under the CIA in 1961 and was transferred to the Defense Department in 1964. It ran South Vietnamese commando raids against North Vietnamese coastal targets, using fast patrol boats purchased quietly from Norway. These raids were ongoing in the days immediately before the Maddox encounter, and North Vietnam likely viewed them as part of a coordinated escalation that also included the Maddox's DESOTO intelligence patrol.
Captain Herrick, commander of the Maddox task force, cabled his superiors at 01:27 local time on the 4th of August that many reported contacts and torpedoes appeared doubtful, citing freak weather effects on radar and overeager sonarmen. He sent multiple follow-up cables recommending a complete evaluation before any further action, and by 18:00 Washington time concluded that most torpedo reports were likely the sonarman hearing the ship's own propeller beat.
Squadron Commander James Stockdale was flying overhead during the 4th of August engagement. In his 1984 book Love and War, he wrote that he had the best seat in the house and that the destroyers were shooting at phantom targets with nothing there but black water and American firepower. His superiors ordered him to keep quiet, and after his later capture he feared his captors would force him to reveal what he knew.