The statement comes from a person who actually is working in the government in the UAE right now: "I used to think the Sunni-Shia tensions in the Gulf States were about power. The more time I spend here, the more I realize how much Gulf Arabs just hate Persians, and it has a lot to do with religion. It's deeper than I realized."

As destructive as it may be, a Sunni-Shia regional war (or even just the Syrian Civil War, which is a regional war by proxy over the corpse of Syria) is the next logical step from a historical perspective. The first step involves a heightened level of self-awareness in the region. This led to Arab nationalism, which failed. That led to Salafism and jihadism, which certain people in the region thought worked because with billions of US dollars in military aid they were able to continue a guerrilla war that made it too costly for the Soviet Union to want to bother staying in Afghanistan. However, global jihadism has failed as well, and even though fanatics may continue to blow themselves up, anyone with half a brain realizes that the West cannot be defeated or converted.

Now the Muslim world has turned inwards, just as Christendom did when it realized it reached its geographical limits, and it's enjoying its wars of religion. Syria is very much like the Thirty Years' War, and I suspect the analogies will continue because the regional players all want to make sure their side wins without being directly involved, but each setback makes them increase their commitment. If ISIS is really crushed in the North, the rebels can expect more support from the West again, and Assad will start to lose again, which will prompt Iran to provide more support, which will see the Saudis try to push Lebanon or Iraq into civil war, which will increase the stakes again.

Obviously, it can all stop if a negotiated peace can be had, but I don't see any sides ready to sit down and talk. Even then, the Middle East is notorious for inconclusive talks. It'll probably be over by 2017, though.