It's actually an interesting reframing of the original problem: allowing a particular regime to remain in power and embark on a very wrong course of action might be the "least worst" option that is practically possible. In all but the worst case regime the rational utilitarians fearing the consequences of violent revolution actually find themselves in agreement with the pacifist absolutists.
It might be that a realistic examination reveals that regime change would be too "expensive", or risks failure either because the current regime wins, or because the replacement is no better ("the king is dead; long live the king").
However, given that analysis, it's still immoral to sit idly by and let events run their course. One would still have, at the very least, the obligation to (a) try to precipitate change in the long term; and (b) possibly contrive to minimize ones own contribution (by way of taxes and other support) to the current regime and its projects.
My impression is that the Iraqi people aren't doing a whole lot in either of those approaches (although I haven't studied it extensively, and what I do know is through the lens of the media). So while your claim may be correct in some cases, I don't see that it's applicable here.
I would say that our nation is us, and the same is true of the Iraqis. The bad things that my nation does (including the entity that it allows to govern) is my responsibility, especially because its acts are enabled because of my production (i.e., taxes, technology I develop, etc.).
The very same thing is true of Iraqis. They allowed their government to continue to run things the way they are.
You might argue that we live in a democracy, and thus change is easier for us. I would reply that (a) the form of government doesn't matter, in the final accounting a government cannot survive without the acquiescence of its people; and (b) fundamental changes in the USA might actually be more difficult, because its government is stable, entrenched, and incredibly strong.