It seems to me that Amir is probably the best embodiment of betrayal. At the moment where Hassan was in the most need of help, he watched. He watched his friend sodomized in an alley. When he was asked, Amir simply dismissed Hassan as a "servant." He did nothing to alleviate his friend's suffering. Hassan needed help and was betrayed by a friend who merely watched. In this, I think that a powerful act of betrayal was evident. Such a moment reflects how betrayal does not happen on a large level, to people that are unknown. Rather, it happens on a personal level to the people we love the most. It is this paradoxical relationship between individuals and betrayal that make it a very compelling theme in the novel. The question becomes how we love people and then find it easy in a moment of temporality to betray them. This is where Amir finds himself at this moment. Amir's betryal of Hassan at this critical moment is what drives both the narrative and his own sense of self as the novel progresses.