The Best Point The Film Makes

(Spoilers)

The fact that he becomes radicalized when he is tortured in Karachi is evident by about the 15th minute. I think there are other points to be made after that.

Hasan basically shuts himself down emotionally afterwards. Sayid offers him so much friendship and he spurns that. Duri offers him love and he spurns that too. I think he ends up being a man wanting so desperately to believe something, that he'll do anything to hang onto it.

Perhaps if he had friends or family left in Pakistan to help him recover emotionally from being tortured he might not have been as suseptible to being radicalized. That might not be true for everyone, but perhaps for some.