Robin Wright writes: Over the past few months, as the size of the Islamic State’s caliphate rapidly shrunk, the Pentagon began citing the number of enemy dead as an important barometer of longer-term success. “We have killed, in conservative estimates, sixty thousand to seventy thousand,” General Raymond Thomas, the head of U.S. Special Operations Command, told the Aspen Security Forum, in July. “They declared an army, they put it on the battlefield, and we went to war with it.”

A high kill rate, which once misled the U.S. military about its prospects in Vietnam, has eased concerns in the U.S. today about future attempts at revenge from isis’s foreign fighters. “We’re not seeing a lot of flow out of the core caliphate, because most of those people are dead now,” Lieutenant General Kenneth McKenzie, Jr., the director of the Pentagon’s Joint Staff, confidently told reporters this month. “They’re unable to manifest the former activities they did to try to pose themselves as a state.”

Yet the calculus is pivotal now that the isis pseudo-caliphate has collapsed: Just how many fighters have survived? Where are they? What threat do they pose? Between 2014 and 2016, the perpetrators of all but four of the forty-two terrorist attacks in the West had some connection to isis, the European Commission’s Radicalization Awareness Network said, in July.

A new report, to be released Tuesday by the Soufan Group and the Global Strategy Network, details some of the answers: At least fifty-six hundred people from thirty-three countries have already gone home—and most countries don’t yet have a head count. On average, twenty to thirty per cent of the foreign fighters from Europe have already returned there—though it’s fifty per cent in Britain, Denmark, and Sweden. Thousands more who fought for isis are stuck near the borders of Turkey, Jordan, or Iraq, and are believed to be trying to get back to their home countries. [Continue reading…]