The second naval attack on August 4, 1964, never actually took place.

While the first clash on August 2 was real, the second one was a ghost. Declassified documents from the National Security Agency show that there were no North Vietnamese boats near the American ships that night. The ships were shooting at shadows. Bad weather and jumpy sonar operators made it look like an attack on their screens. Former U.S. Defense Secretary Robert McNamara even admitted years later that this second attack was totally imaginary.