There is some gratification in the notion that worse comes to worse, we can always let the nukes fly and turn the region into the biggest mirror in history. But, the reality is that such a solution is unsustainable, especially culturally and politically. There are a few of us in this country that are willing to go all the way and have it in them to "become death, the end of things" if it comes to it, but the vast majority of the electorate are nowhere near there. Besides, if we do go for the nuclear option, the cultural damage to our own side will be devastating. What is the point of winning against the barbarians if we then turn into the Third Reich? I guess we'll be alive for sure, but beyond that, it will not be much of an existence.
We just have to see Iraq through. The question is how to minimize the damage and somehow try to get some payback at least financially, e.g. by oil, so that at least the fiscal damage is curtailed somewhat. Iraq certainly will not be a 21st c. nation or a democracy any time soon, but at least they can be stabilized enough to start the process that will take 20 years to complete, while most of our troops are gradually pulled out. We need to put the big-boy pants on and recognize this as a nation.