The Ending en why it was brilliant (spoilers)

I can't find anybody who did see the same thing so let me try to explain.

Maybe it's just because I remember having this discussion as a child in the classroom where I was the only person not getting the cold war stand off logic. At that time (80's) there was a fear that russia would bomb america (or the other way around) and the other would respond leaving the whole earth destroyed. I just could not understand the person pushing the last button. I got the logic over having to respond, but not killing everybody.. This is exactly which happened according to the news items in the movie. But the micro version of this was the climax of the movie where Bauer decides not to shoot Cartwright where he proves his motivation to go after him was not revenge but self preservation and more importantly not to kill the last hope referring to the cold war logic which *beep* the whole planet...