Kieran, I think it depends solely on where one chooses to draw the "US Involvement" line.
"July 1945 - Following the defeat of Nazi Germany, World War II Allies including the U.S., Britain, and Soviet Union, hold the Potsdam Conference in Germany to plan the post-war world. Vietnam is considered a minor item on the agenda.
In order to disarm the Japanese in Vietnam, the Allies divide the country in half at the 16th parallel. Chinese Nationalists will move in and disarm the Japanese north of the parallel while the British will move in and do the same in the south.
During the conference, representatives from France request the return of all French pre-war colonies in Southeast Asia (Indochina). Their request is granted. Vietnam, Laos and Cambodia will once again become French colonies following the removal of the Japanese."
Looks to me like the major powers at Potsdam set the stage. We were involved in that, along with the Soviet Union and Great Britain.
Or, you could use this point:
"July 26, 1950 - United States military involvement in Vietnam begins as President Harry Truman authorizes $15 million in military aid to the French.
American military advisors will accompany the flow of U.S. tanks, planes, artillery and other supplies to Vietnam. Over the next four years, the U.S. will spend $3 Billion on the French war and by 1954 will provide 80 percent of all war supplies used by the French."
Or, maybe this one?
"12 Feb 55 - President Eisenhower's administration sends the first U.S. advisers to South Vietnam to train the South Vietnamese Army"
Yet another?
"May 1961 - President Kennedy sends 400 American Green Beret 'Special Advisors' to South Vietnam to train South Vietnamese soldiers in methods of 'counter-insurgency' in the fight against Viet Cong guerrillas."
The hole that sunk the boat?
"November 22, 1963 - President John F. Kennedy is assassinated in Dallas. Lyndon B. Johnson is sworn in as the 36th U.S. President. He is the fourth President coping with Vietnam and will oversee massive escalation of the war while utilizing many of the same policy advisors who served Kennedy.
November 24, 1963 - President Johnson declares he will not "lose Vietnam" during a meeting with Ambassador Lodge in Washington."
Personally, I see the root cause at Potsdam. When the three "great powers" allowed the concept of colonialism to resurrect itself the die was cast. We've paid for that.
