The last pocket held by IS in Syria is home to thousands of civilians caught in the crossfire.Brett McGurk, the White House envoy for the war against the Islamic State, told a conference in Bahrain on Saturday that “the military mission in Syria is the enduring defeat of ISIS.” He said he expected IS would be defeated over the coming months.“It is very difficult because we are in the last stages, where almost every ISIS fighter is in a suicide belt,” Mr. McGurk said. “It’s very difficult fighting but we will get it done.”On Saturday, a summit on Syria attended by the leaders of Russia, Germany, France and Turkey began in Istanbul. The four issued a joint statement agreeing that there could be no military solution to the war.Syria’s civil war, which began as a popular uprising and then dissolved into a fractured and complex conflict, has raged for more than seven years, shattering the country, leaving hundreds of thousands dead and millions displaced.Last week, United Nations humanitarian official, Jan Egeland said in Geneva that some 15,000-people including Islamic State fighters and their families live in the area.“A lot of civilians there are being attacked from all sides,” Mr. Egeland said.Mr. McGurk said that the United States and the SDF are holding some 700 foreign fighters in Syria, adding that they are determined that “these people cannot get out of Syria to threaten our homelands or yours.” He said the coalition is working with some countries to make sure that “we could try to repatriate these people.”While the process is underway, Mr. McGurk added, the United States is working to ensure that they are housed in a facility inside Syria that meets international standards “so that these people cannot commingle and repeat any of the problems that we’ve seen in the past.”SDF spokesman Kino Gabriel told the Kurdish ANHA news agency on Friday that an international tribunal should be set up to try the foreign Islamic State fighters his group is holding. He said that the SDF has apprehended more than 700 non-Syrian Islamic State fighters in addition to their families.