[berntb]

The reason the Saudis work with Israel seems to be a common and aggressive enemy -- Iran.

But yes, SA is a brutal dictatorship that for political reasons have to be more religious and fanatic than everyone else. Sounds quite like Iran, really.

For the rest, I am no real expert. I would note the similarities with the Shia/Sunni problems and the European religious wars of the 17th century. Then you would answer that those wars were in a more violent and barbaric time. And then we would both sigh, depressed for the state of the Middle East.