It wasn't a debacle. Every intelligence agency on the planet thought Saddam had WMDs. It wasn't Powells mistake if some proved to be untrue.
Yet I'm still very convinced that Saddam ferried what stockpiles he did have out of the country. ANd so are alot of very smart spooks.
He stood up in front of the UN and put up all the evidence that was the basis for the invasion. None of it was confirmed after the invasion - so he and Tenet resigned.