Best we can home for?

From now on I will try to post a link to at least one important IR article a week that everyone should read. This week we have:
The Best We Can Hope For
By HELENE COOPER
New York Times
Published: January 14, 2007
Years of bloody but contained mayhem in Iraq wouldn’t exactly be a happy ending. But consider the alternatives.
1. Best Case Option: United States would cajole or force warring Shiites, Sunnis and Kurds to agree to the standard-cookbook negotiated ending to a civil war.There would be some kind of power-sharing deal among the key combatants, yielding an uneasy cease-fire that would have to be policed for a long time by outside peace keepers, since no warring side would trust another.
2. Mid Range Option: Civil War...But, in the end, the Spanish Civil War stayed Spanish. The Europeans sent money and arms and even volunteers, but they didn’t let the war engulf the continent.
3. Worst Case Option: In that picture, the United States would pull its troops out of Iraq, the civil war would accelerate, and the Shiites, financed by Iran, would conquer one Sunni village after another, driving the Sunnis over the borders and into refugee camps in Saudi Arabia and Jordan...War would then spread throughout the region, with nuclear weapons being launched by Iran.