The Military-Industrial Complex
This is a scenario that's resonated among conspiracy buffs since 1991, after director Oliver Stone made it the premise of his box-office smash "JFK" [source: Canby].We like to think of the slain president as a noble, wise leader, one who would have realized that the burgeoning American involvement in Vietnam's civil war was a potential disaster in the making, and who would have decided to cut his losses early.
Such a decision likely would have irked the dreaded military-industrial complex, the alliance of Pentagon officials and defense contractors that Kennedy's predecessor Dwight Eisenhower had warned Americans about in his farewell speech in 1961. Eisenhower felt that these contractors were gaining enormous influence over what the armed forces spent on weaponry [source: NPR].
So, is it possible that forces inside the military-industrial complex could have arranged the murder of an uncooperative commander in chief? One big problem with the theory is that there's no conclusive proof that JFK actually contemplated preempting the Vietnam War. To the contrary, in a 1964 oral history interview, then-Attorney General Robert F. Kennedy — who himself would be assassinated in 1968 — said that his brother was convinced the U.S. had to remain in Vietnam to challenge the spread of communism [source: Grier].