Good question. I admit most of it is conjecture based on perceived conflicts of interests, and finding motives for seemingly irrational actions. But I am not alone in tha approach - see for example Kupchan's book _The End of the Amercian Era_ which takes a similar line, or for that matter, the way Rusmsfeld and Co. approached intelligence gathering. It is a "deductive" approach instead of an "inductive" one. That is, it starts with finding who had the motive, opportunity and means and then see whether he did it, instead of collecting pieces of evidence and then trying to connect the dots.
Wojtek