If there is one iron law of American history it is that the longer US troops stay in a country, the better the chances of a successful outcome to a war. Germany, Italy, Japan, South Korea: All are places where US troops still remain decades after the wars that brought them there. It is no coincidence that they are also democratic and prosperous. Compare this with the hellish outcome in places like Somalia and Haiti, where US troops entered and then left.
Iraq is likely to be neither Germany nor Somalia - but its odds of the latter outcome now look better because US troops are leaving while the divisions which led Iraq to the precipice of catastrophe in 2006 and 2007 remain fresh and raw. Iraq has had free elections, but the government is dominated by Prime Minister Nouri al Maliki and hard-line Shi'ite Islamists, who refuse to share meaningful power with Sunnis, Kurds, or secular Shi'ites. Deputy Prime Minister Salah al-Mutlaq, a leading Sunni politician, recently told CNN: "The political process is going in a very wrong direction, going toward a dictatorship. People are not going to accept that, and most likely they are going to ask for the division of the country. And this is going to be a disaster.''