Joel Wing summarizes a RAND study from earlier this year:
Overall, the RAND report thinks that the center will hold in Iraq as the U.S. withdraws its forces beginning this year. The major groups in the country are committed to politics now, and the main short-term threat to stability, Nouri al-Maliki, may not even return as prime minister. The Arab-Kurd divide is still a long-term problem that the country needs to overcome. If that comes to a head however, it will be long after U.S. combat forces have exited the country. In the end, RAND believes that Iraqis will determine their own future, and that U.S. power has already reached its apex, and is in fact declining with each day. This has caused fits for some such as outgoing commander of U.S. forces General Ray Oderino and a slew of American think tankers that want to preserve U.S. influence by keeping U.S. troops in Iraq for as long as possible.
For them, Iraq is like a prodigal son that they can’t let go of. The RAND report is also a rebuff to those that constantly fret that Iraq is about to return to major fighting over a never ending list of issues that have come and passed, and others on the horizon. As the study points out, the militants lack the means, internal support, and foreign backing to change the status quo in Iraq, despite their daily acts of violence. The next large bombing will kill many and garner international headlines, but it will not change the status quo within Iraq. While Iraq’s politicians will take their time to put together a new government that doesn’t mean the country is falling apart either, because the major players are all involved in the same process now. Iraq will move ahead on its own clock from now on, and its up to the world to adjust to this new reality.
I hope they're right. But I doubt this will last for long.