It's a little hard to admit that the Sunni-Shi'a split has been around for a long time, is observable in countries far from Iraq, was observed in Iraq by Gertrude Bell and others, and owes its origins to events that took place in the first century of Islam, with consequences that have never been exactly hidden from view.
Did Bush know about Sipah-e-Sahaba, the Sunni terrorist group that targets Shi'a? Did he know of any history of Sunni-Shi'a conflict in Yemen or Lebanon? Is he aware that in Afghanistan the Sunni Taliban massacred the Hazara (an ethnic group descended from Mongols) and would have killed all of them, because they were Shi'a (see Rory Steward, "The Places In-Between" for an account in a hard-to-miss best-seller).
No, apparently he did not.
And because he did not, nor did others in his Administration, they are not about to say, at this point: well, it was there all along. We just missed it. Chalabi didn't tell us. Bernard Lewis underestimated the problem (for god's sake, Lewis co-wrote an article proposing a Sunni monarch - his friend Prince Hassan, without naming him -- to be set on a throne created for him in Iraq by the Americans.
But if the Administration and its loyalists argue that this conflict was not inevitable, and that no one foresaw it, much less thought it was something to welcome and exploit, they have two problems:
1) Why, in 500-600 postings here, was that conflict steadily described as the inevitable outcome of the removal of Saddam Hussein, one that would occur whatever the Americans did or did not do?
2) If it was NOT inevitable, than presumably this outcome was the result of human error. Whose error? Why, the error of the Americans of course. Haven't they been the ones who have irrupted into Iraq, and mucked about with Iraq's otherwise splendidly harmonious sectarian and ethnic arrangements?
So the Bush Administration is going to have to choose what whipping it prefers. Does it wish to be accused of merely making mistake after mistake in "execution" of a perfectly sensible, rational policy, with goals that if achieved would have furthered American and Infidel interests, and weakened the Camp of Islam, but that here and there -- Bremer dissolving the army and accepting de-Ba'athification, for example -- "mistakes were made"?
Or should it choose to take the blame, that it deserves to take, for not understanding very much about Islam, and thus identifying the enemy wrongly in that phrase "the war on terror," and furthermore, not knowing much about Iraq, or how deep and intractable were, and are, and will be, the sectarian and ethnic fissures, and why that is not a bad, but a good thing for us, something that the Bush Administration just cannot seem able to comprehend.
Perhaps it is more than mere obstinacy, an inability to admit how wrong it was (and thus, what a waste most of those trillion dollars, and so many of those soldiers' lives, that were expended after the invasion and the first, possibly justifiable year). Perhaps it is also sentimentality: we can't "just leave these people to kill each other." Of course we can. Our loyalty should be singlemindedly to ourselves, to Americans and to the other Infidel victims of Islam, those threatened most immediately, and those that still have a decade or two to do something to protect themselves.