In the summer of 2012, first reports emerged of so-called “foreign fighters” (FF) leaving their home and residence countries to join the Syrian uprising against the Assad regime. Since then, the number of these “travellers” to the Syrian, and more recently, Iraqi battlefields has grown significantly: From September 2014 to September 2015 alone, the number of FF reportedly doubled and reached 30,000 combatants coming from 104 countries. Experts and government officials have increasingly warned of the potential security threat this phenomenon might also pose to Europe and beyond.

On the occasion of the Netherlands’ presidency of the Council of the European Union (EU) in the first half of 2016, the Netherlands National Coordinator for Security and Counterterrorism (NCTV) commissioned the International Centre for Counter-Terrorism – The Hague (ICCT) to report on the FF phenomenon in the EU. Specifically, this report aims to map the phenomenon and facts surrounding FF in the context of the conflicts in Syria and/or Iraq, as well as the threa assessments and policy responses both at the EU level and within individual EU Member States (MS). As such, this document is not an evaluation of policies, but rather is a charting of the FF situation and responses within the Union.

Utilising data received directly by MS in response to a questionnaire, as well as other public material, ICCT gathered information on the number of FF, their characteristics, MS’ threat assessments, and the policies adopted in response to the phenomenon. Supplemented by open-source data and information from expert consultations, this report provides a close look at the FF phenomenon and responses in a total of 26 MS. Nine countries were selected to be analysed in-depth, representing a mixture of transit and sending countries from across the EU, including MS with the highest absolute and per capita numbers of FF. These nine focus countries are: Austria, Belgium, Bulgaria, Denmark, France, Germany, the Netherlands, Spain, and the United Kingdom. Additionally, the report also examines developments at the EU level in response to the FF phenomenon.

Several challenges were encountered during the data collection period, especially with regards to the number of FF. First, lacking a common and agreed definition of FF, and a central repository for data collected at the MS level, some countries conflate numbers on FF and foreign terrorist fighters, at times adding those involved in terrorism more generally. Second, authorities themselves often lack accurate data or may not disclose their information. Opensource data seldom matches the official government numbers, and many reports use estimates instead of exact numbers, frequently leading to inflated FF numbers. The third challenge is that of the double counting of travellers, returnees, those who died abroad, residents, and citizens.