Wait, wait - let's not conflate the notion of other cultures as rational with the notion that they are moral. The two concepts are not one and the same. In one sense, if I can eliminate the risk of punishment, it's a perfectly rational course of action for me to kill you and take your possessions - the risk is low and the rewards are high - but that hardly makes it moral for me to do so. And on the opposite side of that coin, sacrificing one's own life for the life of a perfect stranger is not really what we would call a rational choice, especially where self-preservation is held paramount, but in many circumstances, it is a highly moral choice.
So when I say that they are rational actors, it should not be taken to mean that everything they do is somehow okay - it's not intended to excuse them, but to explain them. And as I said, this is not least because defining them as "irrational" is not a useful designation - they aren't irrational, it's just a different calculus at work. And you can hardly understand your enemies without first coming to understand how they think.
An effective foreign policy for the 21st century will recognize that any government that systematically supresses human rights lacks legitimacy even if such a government is favored by the majority of its citizens.
And what then are we to make of a state that systematically suppresses the fundamental right of self-determination when it happens to dislike the results? There is no moral high ground in such a position, and no particular legitimacy inheres in such a foreign policy. "We know what's good for you better than you know what's good for you" has been the source of endless troubles throughout the world, literally for millennia, but now we're supposed to embrace that on our own behalf? And what will we say when someone comes to us and says "we know what's good for you better than you do"? Or will it simply be meaningless, because we have the power to impose our will upon others, and nobody has the power to impose theirs on us? In which case, isn't that exactly the same as saying that we have the right by virtue of the fact that we have the might?
Having a universal standard against which to measure the behavior of governments is powerful concept which has been thrown away because of our uncritical acceptance derived from our anti-colonial past of the right of National Self-Determination.
It's been thrown away because it's dangerous. It's a great idea, so long as you're the one who gets to decide which standard will apply. But what will we say when the world decides that laissez-faire capitalism "systematically suppresses the human rights" of the American people - namely, their "right" to free health care, free education, a massive welfare state, and so forth? Upon what grounds will we object if they decide to ignore the right of self-determination among Americans, and simply impose the sort of government they think we deserve?
No, I think it's really best to stay out of the crusade business in the first place. Iraq in its present form will die not because we have the "right" to adjudge its legitimacy, but because it is a danger to us and a danger to others, and because we have the right to defend ourselves from madmen with the ability to kill millions. But because we exercise that right, we have a corresponding responsibility to see that Iraq is reborn a better place. We don't do it because we have the right to remake the world as we see fit - we do it because our desire for self-preservation demands it, and leaves us no other choice. We don't act because we can, or because we have the right - we act because we have to. And then we follow the moral and humane course, and rebuild them better than they were before.