TerrorismISIS's new recruits more than make up for militants killed by coalition forces

For almost every Islamic State militant killed by U.S. and coalition forces, a new fighter is recruited by ISIS supporters in the Middle East or abroad.

U.S. officials have boasted that the coalition’s airstrikes are inflicting great harm on ISIS, using a series of different numbers to support their case. “We’ve taken about 13,000 enemy fighters off the battlefield since the September-October time frame,” Gen. Hawk Carlisle, head of the U.S. Air Force’s Air Combat Command, told reporters at a 1 June Air Force Association breakfast in Arlington, Virginia. Two days later, Deputy Secretary of State Tony Blinken while in Paris told France Inter radio that the strikes had killed “more than 10,000” ISIS militants. On 5 June, Lt. Gen. John Hesterman, the senior U.S. Air Force officer in the Middle East, told a Pentagon press conference that the air campaign was “removing over 1,000 enemy fighters a month from the battlefield.”

Experts say focusing on the enemy body count ignores some trends that are not in favor of coalition forces.

The number of ISIS militants killed by coalition forces are matched or exceeded by the number of fighters ISIS is recruiting. “The strength of ISIS continues to grow, so they’re getting more in from recruits than they are losing through casualties,” said Rick Brennan, a senior political scientist at the Rand Corp. and a former U.S. Army infantry officer who was a civilian advisor to the U.S. military in Iraq from 2006 to 2011. Harleen Gambhir, Counterterrorism Analyst at Institute for the Study of War, is not convinced that ISIS’s recruitment is exceeding its losses. “It’s turning out to be about even,” she told Foreign Policy.

ISIS’s largest source of new fighters is the flood of foreign fighters, many from southern Europe, currently pouring into Iraq and Syria. Coalition air campaigns are doing little to stem that flow. “Recent months have seen an incredible eruption in terms of foreign fighter flow into the Middle East in support of ISIL and its affiliates,” U.S. Army Gen. Joseph Votel, the head of U.S. Special Operations Command, told a 19 May conference in Tampa, Florida. President Barack Obama during his remarks at the G-7 summit in Germany said in addition to forming local Sunni security forces in Iraq, “the other area where we’ve got to make a lot more progress is on stemming the flow of foreign fighters.”

The Obama administration has urged Turkey to better monitor its border with Syria to reduce the flow of European ISIS supporters into Syria, then ultimately into Iraq. “If we can cut off some of that foreign fighter flow then we’re able to isolate and wear out ISIL forces that are already there,” Obama said. “Because we’re taking a lot of them off the battlefield, but if they’re being replenished, then it doesn’t solve the problem over the long term.”

ISIS also recruits from territories under its control. Some of the men and young boys are volunteers, while others are forced to take up arms. ISIS assigns some of the recruits to secure their own neighborhoods, though many more are sent to one of at least ten training camps the group runs in Syria and Iraq. These camps altogether may release at least 500 fighters every four to six weeks to join forces on the front lines. Other insurgent groups that pledge allegiance to ISIS make up the group’s third major stream of new fighters. This is happening in Syria “as ISIS is pushing further and further toward the Syrian central corridor and to the western coastline, and becoming more involved in the ongoing fight that (al Qaeda affiliate) Jabhat al-Nusra and the Syrian rebels are undertaking,” Gambhir said.

Daniel Byman, director of research and a senior fellow in the Center for Middle East Policy at the Brookings Institution cautions, however, that despite ISIS recruitment successes, its ability to recruit is based on its number of victories on the battlefield. “A lot of their recruitment stems from being winners,” he said. If ISIS scales back to avoid taking casualties, it risks “losing recruitment, because part of the excitement of what you do is that you’re bad-ass and you go take the fight to the bad guys,” he added. “So I actually think the Islamic State has a lot of vulnerability on this score, because so much of their reputation is built on being a winner and that’s not something that always stays true.”

However, “they’ve done well by it so far, I have to admit,” Byman said.