“Gary Brecher: War Nerd” is a hidden gem of the internet. His stock in trade is a vast knowledge of military history and deadpan dark humor. Naturally, I like Brecher a lot.
His newest article If It Ain't Fixed, Break It All Up: Cookin' Up A New Me With Cheney is a pretty good survey of the current situation we are facing.
Simplest way to understand it is think about how religion plays out in a place you actually know. Take Europe: the Europeans used to have religious wars all the time, pretty serious ones like the Thirty Years War - a third of the population of Germany wiped out - right up till Europe stopped having religion. And those wars weren't really all about dry theological stuff like what Jesus' middle name was, or what color the priest's collar had to be. On the ground, religious hate like that always translates into tribal hate about sex and hygiene and how those people smell.
Even in California, where it's pretty calm in terms of religious wars, I grew up hearing Brother Art talk about Catholics - "Romans" he called them - worshipping idols and having too many kids and being generally Mexican and dirty. That was the main thing: they smelled, didn't have showers. Come to think of it, Shia are kind of like Islamic Catholic types: stay-behind, ignorant people with too many kids, no money, weird gaudy ways of making religion. That Shia festival where they slash themselves, whip themselves, try to get attention in the street by bleeding on law-abiding hardworking Sunni - it's a lot the way we thought about Catholics. Of course sometime back in the fifties American Catholics turned into just another batch of white people, cleaned up and got on the pill, but that never happened to Shia. For the Sunni, Shia are like rats, swarming up out of the sewers unless you keep them down every minute.
That's the real hate that keeps the power drills and suicide Plymouths powered up in Baghdad. The Sunni who blow themselves up in Shia markets see themselves as pest exterminators for God, cleaning up the neighborhood one bomb at a time. Truth is, it's not hard to understand how a suicide bomber thinks; a lot easier than understanding how an accountant thinks, if you ask me.