Joe Klein, who has been extremely contrite about his extremely minor role in supporting the Iraq war, beats himself up again and pledges never to repeat the mistake:

As for myself, I deeply regret that once, on television in the days before the war, I foolishly — spontaneously — said that going ahead with the invasion might be the right thing to do. I was far more skeptical in print. I never wrote in favor of the war and repeatedly raised the problems that would accompany it, but mere skepticism was an insufficient reaction too. The issue then was as clear as it is now. It demanded a clarity that I failed to summon. The essential principle is immutable: we should never go to war unless we have been attacked or are under direct, immediate threat of attack. Never. And never again.

I almost hate to do this to a guy who feels so bad, but he's massively over-reading the lessons of this episode. There's a general tendency to react too strongly to the most recent event -- to re-fight the last war. My formative experiences in wars were the Gulf war, Bosnia and Kosovo -- wars where  the skeptics who warned about a quagmire, and there were plenty of them, were proven decisively wrong. Because of that, I expected a similar experience. Among other things, I focused entirely on the rationale for war, which I still think was solid, and failed to think very hard about the likely outcome of an American occupation of Iraq.

Klein's argument that "we should never go to war unless we have been attacked or are under direct, immediate threat of attack" is a pretty extreme position. It would rule out not just the intervention in Bosnia and Kosovo, but also the Gulf War, the Korean War, and going to war against Germany in World War II, not to mention obviously Vietnam and World War I. Probably the only wars such a standard would permit would be fighting Japan in World War II and, arguably, the War of 1812.

Now, there are some people who believe that. But does Klein really believe it? He would oppose intervening in Bosnia and Kosovo, the Gulf War and the European theater in World War II? I doubt he's actually embracing a non-interventionist position so sweeping. Rather, I think he's over-reacting to the debacle of the Iraq war in a way that's probably emblematic of a lot of liberal, centrist and realist thought. Gung-ho intervention in World War I led to isolationism in World War II. Success in World War II led to hubris in Vietnam. The sweeping success of the Gulf War led to the hubris of the Iraq war, which will in turn is producing an over-reaction of its own.