Some of you might remember that last year, I read every issue of ISIS's first magazine, Dabiq. That magazine is named for a town in Syria, recently retaken from the Islamic State, which was prophesied to be the site of an apocalyptic battle. "Rumiyah" is the Arabic word for "Rome," and that shift tells you a lot about what you need to know here. ISIS has switched their focus from expanding the caliphate to inspiring attacks on Western "crusader" nations. They provide the ideology, the sense of identity, and colorful guides. "Independent contractors" do the grunt work.
Yes, ISIS has become the Uber of terrorism. You take on the risk, and provide the "car" (which in this case, was an actual car, and a knife) and ISIS gets to put their name on whatever you do. You didn't hire Ivan to drive you home from the bar; you called "an Uber". And a month from now, this won't be Abdul Artan's stabbing spree. It'll be yet another ISIS attack.
And if ISIS is the Uber of terrorism, Rumiyah is the manual they send out to new drivers. Including Abdul Artan,