Via Daily Beast:

The U.S. intelligence community has grown increasingly concerned in recent months about the flow of European and American nationals to fight with al Qaeda-linked affiliates in Syria’s civil war.

While the number of Americans who have traveled to join the jihad in Syria is low, some members of the U.S. intelligence community worry that fighters who receive training and battlefield experience in Syria could return to the West with skills honed by fighting in the country’s civil war.

“At some point all of these people from Europe are going home. All the folks there from all over the world, including the United States, will be coming home if they do not meet their end on the battlefield,” said Rep. Mike Rogers, the Republican chairman of the House Permanent Select Committee on Intelligence, on Tuesday.Intelligence

U.S. intelligence estimates differ on how many Americans have joined the fight with al Qaeda. Some officials say the number could be as high as 60 U.S. citizens, while others put it much lower, at 10. Hundreds of European nationals have joined al Qaeda-linked groups since the civil war began more than two years ago, say U.S. intelligence officials.

Aaron Zelin, a senior fellow at the Washington Institute for Near East Policy and an expert on al Qaeda affiliates in the Middle East and Africa, echoed those estimates. “I have seen anywhere from 10 to 20 Americans based on jihadi forums and Arabic and Western media who have joined extremists in Syria,” he said. “In terms of the European numbers, it’s definitely in the hundreds. It’s closer to 700 or 1,000, according to European officials I have spoken with.”