The recent rise of terrorist activities worldwide and the threat posed by ‘foreign fighters’ (FF) travelling to conflict zones, mostly in Syria and Iraq, represent a growing concern. The scale of the foreign fighters phenomenon has reached unprecedented levels: it has been estimated that by December 2015, between 27 000 and 31 000 persons from at least 86 different countries had joined ISIL/Da’esh and other violent extremist groups (compared to 12 000 by June 2014).
Nationals of several EU Member States have travelled to war zones to join the ranks of the foreign fighters. One of the main challenges has been posed by those who return, as they are associated with a higher risk of engaging in terrorist activity back home.
US consultancy Soufan Group’s estimates reveal that by December 2015, around 5 000 foreign fighters from EU Member States had travelled to Syria to join the civil war. The average rate of returnees reportedly amounts to 20–30 % . A 2016 report by the International Centre for Counter-Terrorism (ICCT) also indicates that an average of 30% of foreign fighters have returned to their countries of departure. According to the report’s EU-wide estimate from end October 2015, the total number of foreign fighters from the EU stood between 3 922 and 4 294. The report further says that the majority – around 2 838 persons – come from France, Germany, the UK and Belgium, the latter having the highest per-capita number of foreign fighters (see the table showing the 10 Member States with the highest FF numbers across the EU, and the numbers of returnees).
The need to stem the increasing flow of foreign fighters has triggered action at international, European and national level, especially in the most affected countries.