Book excerpt: Colonel L. Fletcher Prouty, the former CIA operative known as “X,” offers a history-shaking perspective on the assassination of president John F. Kennedy. His theories were the basis for Oliver Stone’s controversial movie JFK. Prouty believed that Kennedy’s death was a coup d’état, and he backs this belief up with his knowledge of the security arrangements at Dallas and other tidbits that only a CIA insider would know (for example, that every member of Kennedy’s cabinet was abroad at the time of Kennedy’s assassination). His discussion of the elite power base he believes controlled the U.S. government will scare and enlighten anyone who wants to know who was really behind the assassination of John F. Kennedy.