We didn't go in because we didn't want to get bogged down for a decade or longer trying to clean up after toppling the government. That and there was no clear mandate for deposing him.

Cheney, the defense secretary at the time, if you will remember your chain of command, said as much.
Agreed. We had enough reasons not to go in, and Saddam's agreeing to the UN resolutions was one of them.

We all knew it was going to be a difficult war once we jumped in, but he left us little choice.