"There is a temptation to rehearse this observation—that jihadists are modern secular people, with modern political concerns, wearing medieval religious disguise—and make it fit the Islamic State. In fact, much of what the group does looks nonsensical except in light of a sincere, carefully considered commitment to returning civilization to a seventh-century legal environment, and ultimately to bringing about the apocalypse." - Graeme Wood, writing at the Atlantic
In other words, the Islamic State must be viewed through a lens of raw basic Islam of a type Mohammed himself preached and practiced.
Meanwhile, there's at least one idiot at the U.S. State Department who seems to think the only way to defeat ISIS is to find its members jobs (presumably at a $15 an hour minimum wage).