Well it didn't hurt that Saddam had already previously used WMD's (chemical weapons does fit the bill if I recall) on his own people when it pleased him.

Nor that evidence was found during the first war that he not only possessed more than what was found but had moved said weapons across boarders to attempt and save them. Something I believe they also found evidence of in the 2nd war, but of course the media quashed it or did their best to discredit it. (Though for the record I seriously doubt that Syria or Iran would give them back so easily)

I wonder when the inquiry is due to be over and if so what kind of propaganda will be touted to the public of its results or conclusions if any.