It is impossible to prove a hypothesis in absence of facts. At least Sherlock Holmes always thought so.

However, as Sherlock Holmes also said, when you have eliminated the impossible, whatever remains, however improbable, must be the truth.

The key, of course, is to have "whatever remains" be a single scenario. And that, as yet, is nowhere close to the case. That being said, "I don't know" is a perfectly valid response.

However, I do think we can eliminate one or two impossible things. One of them is that the sole reason anyone around the world thought there were WMD in Iraq prior to the war was because Bush and Blair said so. Yet, for some reason, the "Bush lied about WMD being in Iraq" scenario is being touted as a proven fact in many places. Don says, "We now know Iraq no longer possessed these large stores of chemical and biological weapons and that both British and U.S. intelligence information had been exaggerated." (italics mine.) He's not the only one.

It would be nice if some rational skepticism could be applied across the board.