If we withdraw from Iraq, we're going to have to withdraw in defeat. There is only one way to end a war (short of mutual annihilation): with one side in defeat and the other in victory. That's kinda how the whole concept of "war" works, and before we start any war, we must ask ourselves: How far are we willing to go to assure victory? And what do we mean by "victory" anyway?
If we define victory as the removal of Saddam Hussein, or the neutralization of his threat of weapons of mass destruction, we "won" this war years ago: Why are we still there?
If we define victory as the creation of a stable, democratic government friendly to the West (i.e. that will preserve the West's access to Iraqi oil) we might as well wait for pigs to fly. A stable government in Iraq must be Islamic, will probably be Shi'ite, and will never be democratic: Democracy is not a concept which fits well with Islam, at least not as the vast majority of Muslims construe either democracy or Islam.
The only sense in which this war can be won is as conquest and colonialism. The only way to win the war in the long term is to occupy Iraq with Western civilians until the current Muslim population becomes an oppressed minority. We could win the war in the shorter term in the same sense that the Soviets won their conquest of Eastern and Central Europe by simply imposing a tyrannical foreign occupation using draconian oppression of the native population. But without genocide and occupation, such a victory would last only a couple of generations.
We might win this war. It's still a very close thing. If we elect a Republican president and Congress in 2008 they might just have the will to do what it takes to actually win in Iraq. It'll require more torture, more Abu Ghraibs. It'll require civilian reprisals: Hang ten random Iraqis every time an American is killed there and watch these fuckers roll over. If hanging men doesn't work, we can hang women and children. We are just as capable of doing what it takes to win as anyone else; and we have bigger and better guns and more people.
I hope we do not win this war. I hope very explicitly for defeat. Not because I have a shred of sympathy or shared cause with the Muslim world—I don't—but because I hope for a vision of the West, a vision forged in the Enlightenment and at least given lip service in my formative years. Defeat in Iraq would be a win for Islamic ideology and a loss for Enlightenment values, but victory would represent the annihilation of Enlightenment values. A defeat would be a setback, but "victory" would represent unconditional surrender in the larger sense.
The West that I love, and especially the America that I love is not a place, it's not a flag, it's not a uniform, it's not a collection of people, it's not a name; it's a set of ideas, of moral principles. And victory in Iraq would be a defeat for those principles.
Some see these moral principles as a luxury in time of conflict. Perhaps they are; perhaps a moral nation or culture cannot survive against the onslaught of those who hate liberty, hate freedom, hate pleasure, hate joy, and glorify in suffering and death. If so, so be it. I will no more support tyranny wrapped in the Stars and Stripes and reading a Bible than I'll support tyranny wrapped in the Crescent and Star and reading a Koran. If the cause of liberty is doomed, then I am doomed too, and I care not whether I'm doomed in Arabic or English.