At the risk of overposting: Those who express ambivalence or reluctant support for the US occupation of Iraq are practicing a form of "less-evilism." And like all forms of lesser evilism, this one is based on self-delusion.
To be precise-- the delusion is that somehow someway the actions of the US military occupation prevent rather than foment disorder and destruction. The delusion is that the US military won't just cut and run when it suits its purposes no matter what the impact is going to be on Iraqis. The delusion is that somehow someway the humanitarian concerns of those inside/outside either/both parties counts for more than zip in the grand reckoning of capital. Look back in history and you find just this same delusional argument. "Oh we shouldn't be in Vietnam, but now that we are, we just can't leave, and abandon our allies to the revenge of the NLF." But of course that's exactly what the US did do when it suited its own interests. And how about looking back further into US history? How about slavery? "Slavery should not exist, but now that it does, we just can't abolish it. Look at what that will do to the poor slaves." Well, the defeat of Reconstruction proved just how much the Union cared for the welfare of the ex-slaves. So a question, and I won't bother you about this again: When US fatalities increase to 10 or 20 a day from the current 1 or 2, when every shopping mall is filled with SUVs saying bring them home, when every Senator questions "our course" in Iraq because of the increasing disorder, will our poll-minders still be arguing for the US to stay, for humanitarian reasons to be sure, no matter the cost to our well-intentioned military, to prevent the greater evil?