A German woman suspected of supporting the Islamic State was repatriated from Syria along with her three children last month, in the first case of an adult European ISIS member brought home through official channels. On Nov. 22, the family was released from the overcrowded detention camp in northern Syria …

Every expert on transnational jihadism knew that eradicating the Islamic State’s self-declared “caliphate” in Syria and Iraq would not lead to the end of this brutal, malignant movement. Since it had become as much an ideology and a brand as an actual organization, holding physical territory and establishing a proto-state …

Even with its physical “caliphate” in Iraq and Syria in tatters, the Islamic State is still managing to wage a global insurgency, maintaining an operational presence in at least 20 separate countries. The organization’s global diffusion recently led a group of leading terrorism experts to describe ISIS as an “adhocracy,” …