Let's see...so, according to you, after the largest attack on US soil, we immediately decided to NOT go after those responsible,
Are you forgetting that we went into Afghanistan BEFORE Iraq?
but rather were worried about the possibility of another dictator in another country who had nothing to do with it cooperating with our enemies with WMDs he ended up not having?
Well, it's easy to dismiss the threat of WMDs with the clarity of 20/20 hindsight, but to answer your question, yes. Whether or not he had anything to do with 911 was immaterial. It was the threat he posed and the common enemy he had with al Qaida.