NATO mercenaries in Syria

"Sometime in the spring or summer of 2013, history was made in Syria. That was when the number of foreign fighters exceeded that of any previous conflict in the modern history of the Muslim world. There are now over 5,000 Sunni foreign fighters in the war-torn country, including more than a thousand from the West. The previous record-holder -- the 1980s Afghanistan war -- also attracted large numbers overall, but there seems never to have been more than 3,000 to 4,000 foreign fighters at any one time in Afghanistan."