IN THE SUMMER OF 2014, ISIS exploded onto the scene with the speed and spectacle of a revolutionary start-up peddling a new app. It broke rules, took risks, and scoffed at the industry behemoth – Al Qaida. Its gamble paid off. Over the past year, a coalition led by the US has spent USD $3.6 billion on dropping nearly 20,000 bombs on ISIS, first in Iraq and then in Syria. This held them away from Baghdad and blunted their momentum, with the group losing a tenth of its territory so far this year. But ISIS has continued to take entire cities, seizing Ramadi in Iraq and Palmyra in Syria in May alone, while comfortably replenishing more than 10,000 fighters killed in airstrikes.