And, what people seem to miss by concentrating on inspections and disarmament is that there's nothing in an inspections regime to stop Iraq from funding terrorism, or providing bases and training for terrorists. The only way to stop that is through regime change.
Iraq is a nation that harbors terrorists and pays terrorists. The US must act to protect its interests, since we have seen the result of allowing terrorists to flourish. It's not about WMD. It's not about UN resolutions. It's the terrorism, stupid.
Of course, getting WMDs out of Saddam's hands is also a worthy goal, though not sufficient in and of itself (Yes, I know that I'm beginning to ramble...)