It was originally claimed by the National Security Agency that a Second Gulf of Tonkin incident occurred on August 4, 1964, as another sea battle, but instead, evidence was found of "Tonkin ghosts" (false radar images) and not actual North Vietnamese torpedo boats. In the 2003 documentary "The Fog of War", the former United States Secretary of Defense Robert S. McNamara admitted that the August 2 USS "Maddox" attack happened with no Defense Department response, but the August 4 Gulf of Tonkin attack never happened. In 1995, McNamara met with former Vietnam People's Army General Võ Nguyên Giáp to ask what happened on August 4, 1964, in the second Gulf of Tonkin Incident. "Absolutely nothing", Giáp replied. Giáp claimed that the attack had been imaginary.