.. the reason oliver stone chose to focus on the CIA in his conspiracy in JFK.. rather than on the mafia like in Ruby.. is because oliver stone wanted to make the message that Jack Kennedy reformed the CIA since alan Dulles established it as a force for good...

... Jack Kennedy made sure the CIA would be good a good establishment a good authority theis eiz mei awethorrity.. the CIA.. for decades to come was Jack's hope .. that was what oliver stone tried to historically document in JFK.. it had to do with ending the Vietnam war.. the American involvement of which admittedly began in JFk's term... in office...