Kennedy, like all other Presidents, faced intense criticism from both the right and the left, which limited his options. That's where Hitchens fails; he doesn't remember and doesn't describe context.
John F. Kennedy was a moment in time, an image that could only last with his passing, a man who, sans any bullets fired in Dallas, would not have lived long regardless. Had he served out his term(s), he might have led us into better domestic and worse foreign policies; he most certainly would have become merely a fairly decent President.
What is remarkable about the man is what everyone in popdom and the media continues to project into his dead image, the constant striving of the media to concoct an American Royalty where none need exist. Indeed, what is remarkable about JFK is that the frozen image of him and the controversy of his death have far outlived anything remarkable about the man himself.
A pretty-boy President with mammoth health problems and some shady connections slain slightly before his time becomes a legend in the idle minds of those who know too much and think too much of themselves to tell what they know.
It's truly a shame he was assassinated. Had he lived, the Kennedy "mystique" would have withered long before now and Teddy would...well, we won't go there. But he wouldn't be what he is today.
Michael
I read a book called Kennedy's Wars, by Lawrence Freedman, making the case that he was anti-Communist and belligerant to the core and would never have pulled out. But I remain unconvinced because of other things I've read. He was a smart guy and I honestly don't know what he would have done.
I know that his philandering was increasingly exposing him to blackmail and that might have led to his undoing. Who can say?