Nearly eight weeks before the 2 August 1964 Tonkin Gulf Incident, Lyndon Johnson made a statement to reporters at a press conference that the U.S. would defend South Vietnam against Northern aggression. According to John Prados, author of Vietnam: The History of an Unwinnable War, 1945-1975, this promise was a significant part of a series of decisions that contributed to the escalation of the war in Vietnam which can be traced back to the Eisenhower administration. (ref: HAPP 20090602)