This pretty much sums up my thoughts... (co-opted from an article by Brian Doherty):
Anti-warriors are sometimes accused of wanting the U.S. to lose in Iraq, just so they can be right. Not so. But they do want America to stop waging unnecessary wars.
All the stated goals of this war have been won. Saddam gone, check. WMD threat? No need to speak of it again. Democratically elected government in Iraq? A-yup. (Unfortunately, there's still a lot of cleanup required...)
But judging whether the Iraq war and occupation was a good idea, or the right thing to do, based on the principle that things are (or seem like they soon will be) better in the region than they were before the Iraq invasion treats war as merely a neutral policy tool.
The question preceding any decision to go to war shouldn't be as simple as: "Might some long-term good occur out of this?" The real question before a war needs to be: "Is this absolutely necessary given a fair consideration of the horrors and unpredictability of war, and the purpose of the U.S. military?" (Which is not: "make the world a better place, somewhere down the line, even if we have to kill lots of people on the way.")
Additional comment: I know this is a very complicated issue, and I don't think there are easy answers. But I do think the decision to wage war against Iraq was a bad decision, resulting from the agendas of certain government officials who have been more concerned with promoting their particular vision of "America" than anything else. As a Christian, I cannot support that agenda. And that is why I have been against the Iraq war since day one. If anyone cared to know.