So long as we can agree that there are viable reasons for a country to enter into an armed conflict besides protecting their own sovereignty, the point stands. Once you can admit that, then you can begin to consider the merits of those other reasons.
I agree that we don't have a good track record when it comes to intervention, but I don't think that's a sufficient argument for not intervening in the future.
No, it's definitely not revisionist history, but I can understand why you think it is. The truth is that the treatment of his own people and the crazy things he'd do to stay in power played a huge role in the decision to invade Iraq. But don't take my word for it, read the War Resolution yourself:
http://www.gpo.gov/fdsys/pkg/PLAW-107publ243/pdf/PLAW-107publ243.pdf
For your convenience, some of those reasons:
Also don't forget about the Iraq Liberation Act of 1998, passed unanimously in the Senate and with 90% support in the house, with the stated policy to "remove the regime headed by Saddam Hussein from power." That would probably be a good source of the reasons we wanted to do it, right?
https://beta.congress.gov/105/plaws/publ338/PLAW-105publ338.pdf
Some of the reasons:
Unfortunately the administration did sell the war hard publicly on the idea of WMDs, and I think that was a huge mistake. They focussed far too much on ultimately faulty intelligence instead of focusing on what was established fact.
This is a cop out, honestly, and I hear it a lot. Saddam Hussein and his regime were particularly gruesome. Honestly I'd be in favor of doing whatever is possible to stop mad men from committing the sort of atrocities that he was known for, any time, any where. Don't delude yourself into thinking that he was just as bad as every other tyrannical dictator. THAT would be revisionist history. It would be really convenient too. But the truth is much more messy, and creates a much harder moral problem to consider.
I'm in favor of doing whatever is possible to prevent the brutal genocide of the Kurdish people. What's happening right now is not acceptable. I don't like getting involved in foreign conflicts, but when women and children are being executed and in some cases buried alive in mass quantities, and when they're begging for help (http://www.mirror.co.uk/news/world-news/iraqi-who-survived-saddam-hussein-4047266), it's time to step the fuck up.
It's difficult, though. Of course it is. It's very easy to be exhausted with Iraq and avoid getting involved. Administration officials did mislead the public and that makes people very skeptical about what we do there, and for good reason.
The real test of moral and political courage would be the willingness to stand up, acknowledge past mistakes, but still maintain that we're not going to let Islamic authoritarians of any type massacre an ethnic population in the most gruesome manner imaginable.
The easy way out, of course, is to shake our heads and say "not our problem". But that's obvious. Of course it's not our problem. It's the problem of the people getting forced out of their homes and marched to a mountain top to starve to death in the name of Islam, or the child that's holding on to life while getting dirt buried on top of her. It's their problem, but they don't have the means to solve it themselves. So do we let them die?
That answer, to me at least, is obvious. The trickier bit comes in figuring out the best way to help them without actually growing Islamic fundamentalism in the process. That should be the topic of discussion, really. Letting a genocide occur should be a non-option, but instead we need to be asking how we ought to act in a way that doesn't actually encourage this sort of thing in the future or come back to haunt us.