Two days later there were reports of another attack. The crew of the Maddox did not see the torpedo ships , but they acted according to radar and sonar reports. They fired at radar targets. There was a lot of confusion. By the end of the supposed battle, the Navy claimed to have sunken two North Vietnamese torpedo ships.
However, investigations since the incident show that there is no evidence to suggest that there ever were any enemy ships present on August 4, 1964. Around 2:00 PM on August 4, Admiral Sharp was recorded saying that, "He, [Admiral Moore] said many of the reported contacts with torpedoes fired appear doubtful. Freak weather effects on radar and overeager sonar men may have accounted for many reports." A few minutes later, Sharp continued by saying, "It does appear that a lot of these torpedo attacks were from the sonar men, they get keyed up with a thing like this and everything they hear on the sonar is a torpedo." Sharp remained confident that there had been at least one torpedo fired at the Maddox.
A more recent incident is the bombing of the USS Cole. The bombing took place on October 12, 2000. The destroyer had stopped to refuel in the Aden, Yemen harbor. A boat approached the ship and exploded. A forty foot hole was blown in the side of the USS Cole. Seventeen US crewmen were killed and thirty-nine were wounded. The individuals on the small boat also died in the explosion. Some people consider this event to be the first step in what lead to the United States' current War on Terror.
Abd al-Rahim al-Nashiri, and the terrorist organization al-Qaeda, is responsible for organizing the bombing. He was arrested in October of 2002. He is currently being held in prison. Al-Qaeda's roots can be traced back to the Soviet war in Afghanistan. US presence in Afghanistan is due to the existence of al-Qaeda training camps there.
Research sources: http://militaryhistory.about.com/od/vietnamwar/p/gulfoftonkin.htm
I have also included an excerpt from the documentary "The Fog of War." In this scene, Robert McNamara, Secretary of Defense during the incident, explains the Gulf of Tonkin Incident. http://www.youtube.com/watch?v=HODxnUrFX6k