"When in doubt, partition," is the received wisdom among unimaginative diplomats. And what did partition bring by way of stability in the post-World War II era? Korea, Vietnam, India, Palestine, Cyprus, Bosnia -- all places still somehow suffering, politically or economically from the traumas that partition visited upon them. This has to be remembered by anyone who thinks that wielding a geographical kitchen knife will magically resolve deeper political, economic, and cultural problems.

At the same time, some sort of devolution of power in Iraq is inevitable, even advisable. The old centralized, suffocating Arab nationalist Iraqi state, which protected a Sunni-Tikriti minority elite, was a terrible beast; its passing should provoke no regrets. However, any replacement must be acceptable to a majority of Iraqis, including Sunnis. At present, there is no consensus in Iraq. The Shiites are fighting over who will control predominantly Shiite provinces; Sunnis are displeased with the likely future distribution of oil revenues; Kurds don't want to be a part of Iraq, but must weigh this against Turkey's reluctance to have an independent Kurdistan on its southern border.

And hovering over all this is a U.S. that seems to have lost all sense of direction in Iraq, looking frantically for a way out. But only the U.S. can provide the sensible anchor to Iraqi moves to shape national agreement over a new power structure. By pushing too hard too soon, so it can withdraw its troops, the U.S. may simply undermine the process.

The Arab world will react in different ways, depending on what emerges. A violent break-up of Iraq will reinforce the centralizing tendencies in Arab states, even as it might lead, dangerously, to escalating tension between Sunnis and Shiites in mixed Arab societies. On the other hand, a peaceful devolution of power, accompanied by consensual power-sharing arrangements, would be ideal: It could show that there is a middle ground in mixed societies between overbearing state control and the granting of greater power and liberty to minorities. For this outcome to have a better chance of becoming a reality, however, the devolution process should not be imposed by a U.S. timetable.