I see a lot of pundits and politicians saying that Sunnis and Shiites in Iraq have been fighting for a millennium. We need better history than that. The Shiite tribes of the south probably only converted to Shiism in the past 200 years. And, Sunni-Shiite riots per se were rare in 20th century Iraq. Sunnis and Shiites cooperated in the 1920 rebellion against the British. If you read the newspapers in the 1950s and 1960s, you don't see anything about Sunni-Shiite riots. There were peasant/landlord struggles or communists versus Baathists. The kind of sectarian fighting we're seeing now in Iraq is new in its scale and ferocity, and it was the Americans who unleashed it.