According to the
Soufan Group (a New York-based security intelligence consultancy), in 2015 the overall number of foreign combatants in Syria and Iraq was between 27 000 and 30 000. An estimated 5 000 fighters originated in the EU (see Figure 1). The number of foreign
fighters from western Europe has more than doubled since June 2014. Most of them
(almost 3 700) come from just four countries (France, the UK, Germany and Belgium).