Michael Doran and Peter Rough have done a masterful job of sorting out the nature of the challenge that the U.S. now faces in the Middle East. They are right to assert that, to the extent that it has put together a coherent concept, the Trump administration has so far tended to remain bound to the policy options imposed on it by the legacy of the Obama administration both in Syria and in the region at large. That legacy is the result of the former president’s deliberate decision to engage with Iran as if it were a normal nation seeking security and pursuing its raison d’état.