This is worth a read. Grab a coffee and fill your boots.

How ISIS Spread in Syria and Iraq?and How to Stop It - The Atlantic

You don’t have to be a conspiracy theorist to understand why Assad allowed ISIS to put down roots: He needed a threat to show the West why his regime’s survival mattered; he needed to demonstrate that there was a worse Syrian face than his own—that of Abu Bakr al-Baghdadi, ISIS’s leader. (If you are a conspiracy theorist, you would also note the strong intelligence connections that developed between the Syrian Mukhabarat and al-Qaeda in Iraq during the Zarqawi days.)

What’s the pathway out of the Syrian disaster? Based on my reporting, I’d offer several conclusions, which haven’t changed much in the last three years:

  • The best hope for Syria’s survival is a political solution—jointly brokered by the U.S., Russia, Iran, Turkey, and Saudi Arabia—that begins the transition to a new, post-Assad government.
  • But such a political solution will be impossible without a strong, U.S.-backed opposition that can merge with “acceptable” elements of the Syrian army to manage a transition from Assad.
  • This transition process will be fostered by safe zones in the north and south, where humanitarian assistance can be directed, Syrian refugees can return, and political compromise can be rediscovered.
  • If these steps cannot be taken, the result will be the continuing growth of ISIS and other extremist groups, and the full collapse of a fractured Syria into a failed state and terrorist haven. Russian-Iranian military intervention can widen the boundaries of Assad’s rump state, but it cannot rebuild a united Syria.