So .... you are saying that if Bush didn't think Saddam had notable WMDs then he would not have invaded?
That WMDs were the overriding justification and that he had no alterior motive? That if Saddam had stepped down the US military would have packed up and gone home?
Of course not. There are reasons to invade Iraq that transcend Saddam Hussien and his mythical WMD's. Given US's stance toward other brutal dictators, some of which reallt do have WMDs, that line of reasoning is utter BS.
What I'm getting at here is that Bush had a strong motive to lie, did he not? Many sources say that Bush pushed Iraq to the top of the agenda from the first cabinet meeting. Clinton made it a policy - basically saying "Making Iraq a democracy would be a good thing" - true. But Bush made it top priority.
What about the CIA agents who testified that they were getting leaned on to make the intelligence fit the plan? Wouldn't that be witnesses who say otherwise?
What about the grasping at straws - like the aluminum tubes and the links to al Quieda? Not to mention the State of the Union Speech where Bush had to refer to British Intel (Who - according to the Downing St. Memo, already knew that GWB was planning to skew intelligence. No stretch at all to suspect that British intelligence was leaned on, too. Especially given the STRONGER evidence against the Brits! )
If they had better evidence, then they would have used it, most surely. "We cant reveal our intelligence gathering methods" ... why not? they didn't seem to work anyways! Don't we need new ones?
So - motive: We know he wanted to do it, and the neocons wanted to do it 10+ years ago. We know that there are people who say "They put pressure on me to make the facts fit the theory". We know that the evidence against Saddam wasn't as strong as it should have been. We have evidence that the Brits were complicit.
Yes, we know Saddam *had* WMDs - we gave them to him. Thats how we know. But we also know that they break down, and that they wee old. We also know how many were used in Gulf War 1. We also know what the weapons inspectors said. We also know that Saddam didn't have the power to project power against his neighbors - much less the US. Especially with US planes overhead, and our willingness to bomb the crap out of what we thought were weapons.
But maybe you are right. GWB is an utterly moral person and would never use any sort of propaganda to achieve his goals.

Your faith in government is admirable, my friend.