Edward Luttwak can generally be counted on for original thinking on foreign policy, and this is no exception:

It was the hugely ambitious project of the Bush administration to transform the entire Middle East by remaking Iraq into an irresistible model of prosperous democracy. Having failed in that worthy purpose, another, more prosaic result has inadvertently been achieved: divide and rule, the classic formula for imperial power on the cheap. The ancient antipathy between Sunni and Shiite has become a dynamic conflict, not just within Iraq but across the Middle East, and key protagonists on each side seek the support of American power.

The whole thing is worth reading. Of course, even if Luttwak assesses the situation correctly, the question is how well this administration — or the next — will take advantage.