It turns out the Iraqis are having a bit of trouble with their constitution. As with so many things (reconstruction, insurgents, democracy, oil, etc. etc. etc.), I think the administration has vastly underestimated the difficulty of this task. True to character, they neglected the difficulties. Had they been paying attention, they may have noticed another country that had its own trouble coming to grip with the issue of federalism. After seven years of failure, they tried again. That didn't really get the job done either--sixty one years later the country nearly destroyed itself in an astonishingly brutal civil war.
The population of the United States was 31 million in 1860, and about 620,000 people died. Iraq has about 26 million people (hey, surely we can trust the CIA about Iraq, right?). I don't know that anyone can really say how many civilians have did, but this site says 25,000. Will Iraq dissolve into civil war? I bet it does, unfortunately. And I bet the issue will be federalism. Just like here.