ISIS’s use of tunnels has evolved as a mean to launch sneak attacks and collect intelligence with cheap UAVs: “In all of the areas that I have visited, ISIS dug a complicated network of tunnels. And so what they’re able to do is they retreat inside the tunnels. And then from there, they’re able to send a drone up into the air. So they’re completely protected and unseen from our surveillance.” Says Rukmini Callimachi, who covers ISIS for the New York Times.
