The British-laid borders for Iraq were a mistake
"It never should have been created in its current international borders. The Ottomans had ruled it for 400 years as three different provinces – the Kurds, the Sunnis and the Shiites – Mosul, Baghdad and Basra. That was the right solution. The British made a mistake." Asked whether the borders should be reconsidered, Holbrooke replied, "I’ve thought a lot about that… I think, in 1991, the first Bush administration, working with the Turks, could have done it. …[But] I think the moment to correct the Churchillian mistake of 1922 is passed, which means we are in a terrifically difficult problem.”