It was pretty clear cut to the point that France, Germany, Russia and China voted against Resolution 1441 in the UN, and there was unprecedented demonstrations across the globe against it.

The only reason that we suspected he had chemical war systems is that the US sold him those chemical war systems in the 1980s to use against Iran. I'm not sure how ready or what level of disrepair they were in 20 years later.

Removing Saddam absolutely was wrong strategically, and lead to about a million people dying.