Actually, most of the UNSC resolutions mentioned in the AUMF in Iraq authorized all means to enforce the provisions of the resolution. They were permissive. I'm not sure to which UNSC resolution you're referring though.
That's your takeaway. Yes, WMD's were a large factor in making the case for the invasion but, only an incurious, disinterested person would think that was the only reason.
When the AUMF was passed, it was in the news for several days. I distinctly remember news accounts covering the human rights abuses, Oil for Food corruption, draining the wetlands, shooting on our forces in the no-fly zone, continued threats to Kuwait, running citizens through plastics shredders, providing safe haven to the world's most notorious terrorists, paying the families of suicide bombers, throwing the inspectors out in 1998, and pretty much non-stop bluster for over a decade from Hussein.
I also remember Salman Pak and now we know, Zarqawi fled there from Afghanistan.
Can't help if you don't pay attention.
I wonder what happened to that program...