Dan Drezner attributes his original support for invading Iraq to U.S. successes in the ’90s:

Ironically, for all the Gen-Xer tropes about irony and cynicism, the foreign policy arc of our generation looked pretty damn optimistic until March 2003. Indeed, reading the above paragraphs I can recall my attitudes about the use of force in 2002 and 2003. America’s use of force during the 1990s — and, at the time, Operation Enduring Freedom — had been limited in scope and pretty efficient in its execution. Furthermore, the foreign policy principals who were planning the Second Gulf War had run the first one, which, again, had gone pretty well. So yes, I think I had a generational bias — I badly overestimated the capacities of George W. Bush’s national security and foreign policfy hands.

I’ve seen this argument made a few different times now, and it’s not very satisfying. If there was one thing that invading Iraq, toppling its government, and then replacing it with a new one were not, it was a military operation that was “limited in scope.” This wasn’t a case of bombing a country to force it to give up a rebellious province, as in Kosovo, or seeking to drive an occupying army out of another country. What was being proposed in 2002-03 was entirely different in its goals and ambitions from anything that the U.S. had done in the ’90s, so why would one conclude that success in the brief, limited wars of the ’90s told us very much about our government’s ability to overthrow and then replace another government?

The second part doesn’t make much sense to me, either. Granted, many of the people around George W. Bush had acquired a reputation for competence in his father’s administration during the Gulf War, but it seems to me this overlooks why they had acquired this reputation. They and the elder Bush were perceived as competent in no small part because the administration had prepared to use overwhelming force to achieve a limited objective after assembling broad international support, and then they refrained from marching on Baghdad once they had achieved the objective of driving Iraqi forces out of Kuwait. The people that served in George H.W. Bush’s administration appeared as competent as they did because they were carrying out the less ambitious policy of a president with far more foreign policy experience. George W. Bush proposed an extremely ambitious policy while having absolutely none of that experience, and it’s not a coincidence that a lot of the people around him ended up being and appearing incompetent and foolish when they tried to carry it out.

That isn’t to excuse their failures, but it is to say that it was always clearly a mistake to trust someone as inexperienced in foreign policy as Bush to oversee such an ambitious policy successfully. By the fall of 2002, it should have already been clear that the George W. Bush’s administration was trying to do something far more ambitious and risky without making the same preparations or gathering similar international backing. Whether it was assembling too small of a force for the invasion or failing in their diplomatic efforts, the people around George W. Bush were already doing an extremely poor job long before the invasion started. Then again, it shouldn’t be that surprising that they didn’t know what they were doing, because they were proposing to do something that the U.S. had not really done before.

I was in college in the late ’90s, and had already been appalled by the war in Kosovo, so I was always much more likely to oppose invading Iraq than most Americans. Where Drezner and Chait saw interventions in the ’90s as a series of success stories, I grew up seeing them as mostly unnecessary actions in conflicts in which the U.S. shouldn’t be involved. The war in Kosovo was blatantly illegal and unjustified as far as I was concerned, and the U.S. and NATO had no business doing what they did. That was initially how I looked at the proposed invasion of Iraq, and then I started to realize how much worse invading Iraq would be. While there were some similarities between U.S. interventions in the ’90s and the proposed invasion, the thing that struck me then and later was that it was a huge departure from even very recent U.S. foreign policy tradition. It wasn’t just that the Iraq war was unnecessary and illegal, though it was clearly both of those things, but that it was profoundly wrong to attack another country without just cause, which the U.S. and its allies definitely did not have. Preventive war was and is wrong in principle, so I never doubted that invading Iraq in the name of “prevention” was morally indefensible.