JFK's mistakes which got him killed were two fold.
One, he underestimated the importance of Dimona not just to Israel but to the International Jews behind Israel. He did not know that Israel getting nukes was part of the Jewish Master plan and that by blocking that plan of the Jews, he was jeopardizing his own life. JFK had not seen the truth about Jewish control of the world. He thought his position as American POTUS really meant that he had power to influence big decisions like Israel not being allowed to develop nukes. JFK did not know that his replacement was already waiting in the wings to take his place if he asserted his own personal control outside of the will of his Jewish masters. All it would take is just one well placed bullet to get rid of him and then Israel could develop all the nukes it wanted without any American oversight whatsoever.
His second mistake is believing that he could not be easily assassinated while he was President. Believing his position as POTUS protected him, he underestimated the ability and the determination of the Jewish enemy to replace him. JFK didn't know that the U.S. Secret Service was compromised at the top and that instead of protecting him, the U.S. Secret Service would stand down and allow his assassination. JFK didn't know that the very motorcade he was in was a carefully crafted assassination tool. He could not have known that the Presidential Limousine would be driven to a pre arranged kill zone where everyone in and outside of the Limo would be complicit in his assassination. And he certainly did not know that his own wife and the mother of his children would be the trigger woman who would end his life and Presidency. JFK underestimated (((them))) and how treacherous (((they))) can be when they really want to do something.