I agree that the time to "walk away" (or rather, ignore intra-party disputes among squabbling Arabs entirely, other than to air-drop ammunition to both sides if one is cynical enough) was 1990; I believe that GHW Bush made the wrong choice by getting involved (heck, I could even point out, as a pro-Zionist, that Iraq was not lobbing Scuds at Israel until after Bush decided to get involved).
But what's done is done. It is plainly not 1990 anymore. Saddam had no grudge against us then, but he does now. Now, on the one hand I don't (in principle) deny the Right of a Sovereign State to develop weapons with or without UN approval (which is what we mean by the term "Sovereign") and I am hardly convinced of Iraqi involvement in the 9/11 attack -- it was largely a Taliban and rogue-Saudi operation. On the other hand, the evidence for Iraqi complicity in the 1993 WTC center attack and possible complicity in the OKC bombing is, I think, more damning than the hyper-pacifists want to admit -- I would argue that it's supremely unlikely that the pre-Gulf War, US-supported Saddam Hussein would have ever initiated such attacks, but what's-been-done-is-done as far as the Gulf War and IMHO these attacks on US soil can reasonably be considered as a Casus Belli justifying some sort of US response (Clinton was just too busy invading Somalia and bombing aspirin factories to trouble himself therewith, I guess).
I shudder to think what the occupation and imposition of a Western government in Iraq will lead to 10 years down the road. Not to mention the costs involved either. I am astounded at the lack of any discussion of an exit strategy.
Likewise.