National Security Action Memorandum # 263 [dated Oct. 11, 1963]At a NSC meeting on November 15, 1963 President John F. Kennedy is said to have taken substantially the same position he had taken with New York Times columnist Arthur Krock a month earlier when he said that the U.S. shouldn't intervene in a "civil disturbance caused by guerrillas". Also on November 15th, Defence Secretary McNamara predicted that the U.S. military role in Vietnam would end by the end of 1965 and the U.S. government announced that the first 1000 of the 15,000 U.S. soldiers then in Vietnam would be home before Christmas 1963. This policy shift is now clearly documented in the recently declassified
On November 22, 1963 those orders were cancelled.
This reversal of Kennedy's policy was to ultimately cause millions of Vietnamese deaths together with more than 58,000 Americans. It was announced by President Lyndon B. Johnson on November 24, 1963. This reversal is outlined in the recently declassified National Security Action Memorandum Number 273 dated November 21, 1963. It was written and dated the day before Kennedy was assassinated!
It wasn't written by John F Kennedy and it wasn't written by Lee Harvey Oswald either but I don't think those that wrote it thought that Kennedy would ever see it