From the ongoing discussion on Slate, Zakaria has one of the better posts so far:

The most anti-American and expansionist regime in the Middle East has disappeared. An actual and potential threat to Israel, Saudi Arabia, Iran, and Kuwait has been eliminated. A violent, rejectionist state has faced consequences. This has had a sobering effect on the region: See Syria and Libya's recent behavior. Given our interest in a stable Middle East, this is good.

Given our growing interest in a more decent Middle East it is even better. For the last few decades we have defined deviancy down in that region. Behavior that would be utterly unacceptable from other countries gets a pass because it's the Middle East. If we learned tomorrow that, say, the Brazilian government was supporting various terror groups, trafficking in chemical and biological agents, and allowing its media to glorify anti-American violence, we would be appalled. When it's Syria we shrug our shoulders and say, "It's the Middle East."

Yes.

This is a common thread in the thought of liberals who supported the war. Some anti-war types want to either minimize or openly mock the association of Iraq with the radical, backwards cultural malaise that encompasses the Middle East like no other geographical region in the world today.

These are quite intelligent thinkers, and all but perhaps one of them doesn't seem to have a problem making the link between ousting Saddam and its ramifications to the War on Terror:

This is the real connection to 9/11. After 9/11 we came to realize that we couldn't let the Middle East keep festering in its dysfunction and hatreds. It was breeding anti-Americanism and terror. With Iraq in particular, business as usual was becoming increasingly difficult. Throughout this discussion we have assumed that there was a simple, viable alternative to war with Iraq, the continuation of the status-quo, i.e., sanctions plus the almost weekly bombing of the no-fly zones. In fact, that isn't really true. America's Iraq policy was broken. You have to contrast the dangers of acting in Iraq with the dangers of not acting and ask what would things have looked like had we simply kicked this can down the road.

He then goes on to point out that, no, ideally war is not the best way for reform to happen in a country, but that sometimes it is necessary.

As they say, go read the whole thing.