Authoritarians are much better than democrats at quickly bringing order in such a frightening environment. This is mainly because it is easier and more efficient to impose martial law than to build political consensus. The volatility of democratic transitions creates demand for authoritarianism. If a country has more experience with dictators than with democrats, this demand may be second nature.
This is essentially what has happened in Russia and in warlord-dominated Afghanistan, and the United States may quickly find itself forced to support an authoritarian regime in Iraq to prevent the country from becoming either an Iranian satellite or an al-Qaida training camp.
In the end, this option might not be as unsavory as it sounds. Before Iraq can become a democracy, it must become a country safe enough for open political debate. As so many have argued, the violence in Iraq requires a political, not a military, solution. And as Bismarck once said, politics is the art of the possible.