Thousands of sympathetic Muslims flocked to Iraq and Syria to join the idealistic cause. In the middle of 2015 it was estimated that 20,000 foreigners were fighting for ISIS, including 5,000 Europeans. Although official counts of ISIS fighters range between 30,000 and 80,000, the former number seems less likely as official body counts of deceased ISIS fighters released by the US have now exceeded 20,000. The latter number of 80,000 fighters, released by the Russian government, is still conservative compared to Kurdish reports of 200,000 ISIS fighters.
