5 June NY Times commentary - A Million Little Pieces by David Brooks (requires Times Select subscription).

... There is no social trust between Sunnis and Shiites, the federalists observed. There is a winner-take-all mentality, which is not conducive to compromise. There is no tradition of impartial rule or impersonal justice, making it hard to establish big national institutions that won’t favor one tribe or sect.

Biden, Gelb and the federalists suggested a devolution of power to the regions, as envisioned by the Iraqi constitution.

Everybody out of power sympathized with their diagnosis, but everybody in power rejected it...

Republicans, Democrats and others went ahead as if a solution could come from the center. The Republicans supported the surge, dependent on the performance of a nonsectarian national military. Democrats imagined that if they came up with the right array of benchmarks, timetables and incentives, they could induce Iraqi leaders to cut deals and make peace. A collection of smart, bipartisan people wrote the Baker-Hamilton report, based on the supposition that regional governments could work with the Iraqi center to create stability from the top down.

Now it’s a year later, and where are we?...