Bad: The two lines of thinking are now dichotomized into "war" and "anti-war"camps.
One mighty fine lesson in all of this is that not only is war hell, but it's a hell of a blunt tool for achieving political aims. After long periods of peace rich, old men eventually begin to think that a little selective warfare overseas is a good idea for king-making, and now we have a handy refutation. Yet that nevertheless doesn't change the fact that the war the rich, old (arrogant and very stupid) men proposed has been engaged. It ain't as easy as war or no war.
If we pull out now, even slowly, as Kevin suggests, we doom Iraq to civil war. Fortunately, pulling out and staying aren't the only two options. Unfortunately, the third option won't happen under Bush. It bears mentioning even so.
Iraq's future depends on extremely strong control. This can't happen from within the country without installing another Saddam, and the US can't do it, either (even if we had the manpower, our efforts would fuel the resistance). The only solution is an outside coalition of countries--the UN is probably the best candidate--who will have the long-term commitment and who will not by their very presence feed the resistance.
A multinational force would have to mainly keep the peace and allow the democracy in Iraq to function on a local level. A constitution, a body of law and the structures to support it, shouldn't be rushed just to achieve a paper democracy. They need to be carefully considered to support the country through future instability. A multinational force could funtion as a the national government and as the police, working very slowly with the developing country to move toward full independence. This would allow the necessary supporting elements of a democracy to function for some years before Iraq lost its training wheels: a free press, an education system, infrastructure, health care, and a growing economy.
And what about the tripartite population? Although I'm slow in coming to this conclusion, Iraq is probably best left in its current, hybrid form. The three main populations could actually contribute to long-term stability in a functioning democracy. As one good example, following Indian independence, the country war partitioned into a Muslim and non-Muslim state. The homogenous Muslim state (Pakistan) has been wracked by corruption and never managed a functioning democracy. The multi-ethnic Indian state, despite enormous difficulties, has been a functioning democracy for all but about five years of its nearly 60 in existence. Diversity is good for democracies.
As long as the US mainly has its own interests in mind (as it surely does now), it will have no interest in doing the long-term work needed to build a successful democracy. So staying in the current mode isn't a successful scenario. Pulling out will doom the country to civil war and ensure that the chaos is replaced by another strongman. Also not a successful scenario.
Let's abandon the practice of feeling like we have to choose one or the other of those shitty solutions.