No. Not possible. He was a confused amateur, who seems to have been looking for some meaning in life after having been brought up by extreme leftist parents with no sense.
That's what I think, too. This doesn't mean that he wasn't being used by others, though - ranging from his father to Michael Moore. He sounds too innocent for his own good, and I wouldn't be surprised if somebody convinced him that he could "negotiate" with AQ or take a "message of peace" to them.