On WMD? Yup
On removing a tyrant from power? Fuck no.
The biggest mistake the USA made was leaving Iraq too early in the first place and leaving a vacuum that allowed ISIS to creep in.
On Iraq, I was serving with an Iraqi born soldier (serving in the CAF) during that invasion. He told me his family was delighted as hell that Saddam got his ass kicked (there is a reason they immigrated to Canada and it wasn't the weather). He did tell me at the time, in his personal opinion, that Iraq needed to be broken up as a nation as the factions would never get along (especially Sunni and Shia), Take his comments for what they are worth.