Originally posted by the Voice of America. Voice of America content is produced by the Voice of America, a United States federal government-sponsored entity, and is in the public domain. Chances Growing Captured Islamic State Fighters Will Return to Battlefield Jeff Seldin U.S. counterterrorism officials are increasingly worried Islamic State fighters captured as the terror group's caliphate collapsed in Syria will find their way back to the battlefield. The concern, they say, is most acute for the approximately 2,000 foreign fighters who are being kept in a state of limbo, held in makeshift prisons run by the U.S.-backed Syrian Democratic Forces as their home countries refuse to take them back. "We've gotten kind of fatalistic about this," Russell Travers, acting director of the U.S. National Counterterrorism Center, said Friday. "There's a growing likelihood that eventually we could see many of these foreign fighters again when they've broken out of prison or been released," he told an audience at the Washington Institute for Near East Policy. "The greatest midterm concern is the retention of those prisoners and not bolstering the [Islamic State] ranks and not seeing a foreign fighter outflow from Syria." For months, U.S. officials at the State Department and the Pentagon have urged countries, especially those who joined the coalition to defeat IS, to repatriate and prosecute their citizens or residents who left to fight for the self-declared caliphate. But those pleas have largely gone nowhere, as European countries especially have raised concerns, arguing their legal systems will not allow for the successful prosecution of IS fighters whose alleged crimes were committed thousands of kilometers away. .