I agree. My case, since shortly after 9/11, was that we needed to take Iraq down in order to finish off our 12 year war there. Our "containment" was a losing proposition, with major security council members beginning to make their own separate peace deals with Saddam. It was only a matter of time before the containment crumbled completely.
Much of our terrorist problem is Wahab, financed by the Saudis. But we couldn't apply the necessary intimidation to the Saudis as long as we needed them for the containment of Iraq. Taking down Saddam freed us from the Saudis. And the effects of that are only beginning to be felt.
We couldn't properly intimidate the Saudis while Saddam was still standing. Beyond that, Saddam was an important symbol, refuge, source of finance, and source of inspiration that had to go or the terrorists could never be beaten. Thats even if he wasn't backing Al Qaeda, which there was and is plenty of evidence of the connections between them dating from the first World Trade Center bombing. The evidence is that Al Qaeda provided the cannon fodder, and Saddam provided the technical assistance.
Look at the long faces on Arabs everywhere outside of Iraq. They don't care what he did to other Arabs and other Muslims, the mere fact that he was against the Americans was enough to make him a hero. And that means that bringing him down was job one.
I liken it to being faced with a mob in an alley. You pick the biggest, mouthiest, and ultimately the most vulnerable one, and jump on him. The others will lose their focus and back down at least for a moment, which may be all you need to save yourself.
Furthermore, you have people say that Iraq with Saddam was not a threat. It is a threat, just like any other terror regime like the Palestinian Authority, Syria or Iran, for the simple reason these places have terrorist friendly haracteristics that in turn spur threats and allow attacks. That failure to understand this led us to believe the Taliban BEFORE 9/11 was a not threat, even though it was.
This is a concept too many people can't seem to grasp.