Responding to foreign fighters: An overview of the main challenges (1)


The foreign fighters phenomenon is currently omnipresent on the agenda of police officers, prosecutors, de-radicalisation experts, researchers, policy makers, municipalities, governments, international organisations and think tanks. The problem is too complex and multi-faceted to analyse in just a few pages. Therefore, the following article, based on a speech presented to the Council of Europe’s Committee on Political Affairs and Democracy on 16 March 2015, should merely be seen as a quick and elementary snap-shot, providing some basic features of the current problem.

This article will address four points: 1) General information on the scale of the phenomenon; 2) Root causes; 3) Implications for countries/societies of origin and 4) Responses. A special emphasis will be put on the root causes and the responses, which are key elements in understanding and addressing the phenomenon.

1. General information on the scale of the phenomenon
Almost every article or contribution on foreign fighters starts by stating that this is not a new phenomenon and indeed, it is not. Osama Bin Laden is probably one of the most famous former foreign fighters.(2) What is new these days is the scale of the threat.(3) On 26 January of this year, Peter Neumann, Director of the International Centre for the Study of Radicalisation and Political Violence, wrote that it has been estimated that the number of foreign fighters in Syria/Iraq exceeds 20,000. The estimated worldwide total is 20,730, surpassing the conflict in Afghanistan in the 1980s.(4) According to these estimates, nearly a fifth of the foreign fighters in Syria and Iraq, almost 4,000, consists of residents or nationals of Western European countries.(5) Neumann notes that this nearly doubles his organisation’s estimate of December 2013, which means that “the flow of Westerners travelling to Syria is [indeed] increasing at an alarming rate.”(6) Although the problem is of course most serious for Syria’s neighbouring countries – with up to 11,000 foreign fighters, the Middle East remains the dominant source of foreigners in the conflict(7) – the focus of this article will be on the European context.
Neumann notes that the highest populated European countries – France, the UK, and Germany – also produce the highest numbers of fighters (1,200, 500-600 and 500-600). However, the most heavily affected countries are Belgium (440, up to 40 per million inhabitants), Denmark (100-150, up to 27 per million inhabitants), and Sweden (150-180, up to 19 per million inhabitants).(8)

Nevertheless, it is important to underline the lack of a generally accepted definition of ‘foreign fighters’. Various documents, including the legally binding UN Security Council resolution 2178 (2014),(9) use the notion ‘foreign terrorist fighters’ to define, “individuals who travel to a State other than their States of residence or nationality for the purpose of the perpetration, planning, or preparation of, or participation in, terrorist acts, or the providing or receiving of terrorist training, including in connection with armed conflict”.

However, proper consideration should be paid to the fact that not all foreign fighters can be seen as such. In addition, a lack of clarity regarding a universal definition of ‘terrorism’ persists, due to the lack of consensus on this highly political issue.
Indeed, what is a terrorist? In some jurisdictions, is considered terrorist an individual committing specific acts of terrorism, targeting the civilian population. For others, it may suffice if the person in question joins a designated terrorist organisation, such as the Al-Nusrah Front or ISIS, regardless of that person’s individual acts. It is important to consider that countries adopt different definitions of ‘terrorism’, which will affect their implementation of the provisions of Resolution 2178.(10)

2. Root causes
There are many ingredients for a person to radicalise, but the recipe is always different. Indeed, each radicalisation process is to some extent unique and individuals will go to Syria for different reasons.
This diversity in the radicalisation process makes it extremely difficult to come up with the solution to the problem. This point will be further elaborated in section 4. Reasons why young Europeans radicalise and choose to fight in Syria or Iraq can be, for instance, of a personal, ideological or religious nature.
Personal reasons are probably the most important reasons and can include a perceived lack of future perspectives in their country of origin, a desire to achieve status or to feel and become part of a group (comradery), as well as a thirst to find an identity and adventure. Psychological health issues might also play a role.

From an ideological point of view, some youngsters leaving for Syria or Iraq face feelings of angriness or disillusionment, which may be caused by the events in the Middle East, in particular the injustice suffered by the Syrian people and the perceived indifference of the West.
As for the religious dimension, some young Muslims may be struggling with fundamental questions on life. Instead of addressing religious leaders for answers, they create their own Do-It-Yourself or DIY Islam in basements or through the Internet, becoming vulnerable to manipulation and recruitment.
In addition, the political climate in some Western countries, as well as the (perceived) discrimination on the labour market, may push away youngsters from their society of origin, increasing their marginalization.
It is also important to stress that, as the conflict in Syria evolves, also the motivations of foreign fighters may change. While someone initially may have gone to Syria for ideological reasons, hoping to assist the local population, he or she may have chosen to remain in order to support groups such as ISIS. Others might end up, perhaps also for practical reasons – such as the lack of financial resources – in criminal organisations, involved in the trafficking of arms, drugs and human beings. Clearly, there is a need to develop a far better understanding of drivers/push and pull factors of foreign fighters.

3. Implications for countries/societies of origin
Clearly, the impact of the conflict in Syria and Iraq is most serious for these countries themselves, in terms of fear, destruction, loss of innocent lives etc. Also neighbouring states, which have to accommodate hundreds of thousands of refugees, and which may be confronted with a spill-over of the conflict, suffer greatly from the conflict. However, for Europe, the biggest fear is undoubtedly to face a Madrid or London-style attack from foreign fighters returning to their country of origin. But how big is the risk that such an attack occurs? Research has shown that “[…] of all of those who have been convicted of jihadi terrorism related activities in Europe between 2001 and 2009, about twelve percent had been abroad prior to their attack, either for ideological training, military training or participation in foreign conflicts.”(11) Even though this percentage is relatively small, the absolute numbers of foreign fighters are rising, and thus are the chances of an attack, in view of the applicability of that same percentage to higher numbers. Furthermore, it should be considered that, despite all calculations based on percentages, in the end only one returnee may suffice to execute a successful attack, as exemplified by the attacks in Toulouse and Brussels.
Additionally, sympathisers with or emulators of violent jihad might also pose a risk, even if they do not go to Syria or Iraq.
These extremists might engage in copycat crimes at home that can also cause serious harm, without having crossed any borders, as was the case in recent incidents and attacks in Australia, Canada and Denmark. In addition to lone actor attacks, there is also the risk of the formation of new or the strengthening of existing terrorist networks. Al Qaida was basically established by a network of former foreign fighters at the end of the Soviet intervention in Afghanistan in the late 1980s. Since the beginning of the armed conflict in Syria in 2011, a higher number of foreign fighters has been identified than during ten years of Afghan war. It is believed that networks are now being formed between individuals (either within Iraq and Syria or with individuals residing in other countries, including their home countries) and organisations as such (see for instance Boko Haram’s pledge of allegiance to the Islamic State).(12)

4. Responses
To stem the flow of foreign fighters to Syria and Iraq and to counter the risk returnees may pose, various responses are available at both the national and international level. These include de-radicalisation programmes, criminal prosecutions and administrative sanctions, including the withdrawal of passports and even citizenships. Even though the most recent national and international agreements demonstrate a greater focus on the preventative side than was the case in the past – an example is resolution 2178, which greatly emphasizes the importance of international law – in practice, States are drawn by repressive measures.
However, repressive approaches alone might not be effective and could even be counter-productive.(13) A balance should be made between various measures, and States should arguably focus more on prevention policies, instead of fighting symptoms, which do not really address the underlying issue. Preventive measures, however, will contribute to effective policies in the long term.
Despite the fact that the success of these ‘soft’ measures is more difficult to assess than repressive measures – in fact, how can you prove that someone did not radicalise? – States should invest in prevention, addressing the root causes and contributing to a sustainable approach of the foreign fighters’ phenomenon.

Possible solutions include measures at individual level (i.e. establish an emergency phone line for parents with radicalized children), at group level (offer a credible counter-narrative, preferably from a former and disillusioned foreign fighter), but also at the level of the State (eradicate discrimination in the labor market, offer job opportunities and encourage social inclusion). Too often, statements by political leaders undermine the positive effects of social inclusion policies and deteriorate the situation.
Additionally, several repressive measures are nowadays being proposed and adopted by a number of governments, but their effectiveness and necessity might be debatable. An example is the call for new terrorism legislation, while the necessity is dubious, and the inadequacy of the existing legislation not proven. Also the effectiveness and necessity of the measure aimed at withdrawing a foreign fighter’s passport and even citizenship should be critically examined. It rather appears to be simply a symbolic measure, meant to brand the foreign fighter as an outcast of society. Indeed, there is a clear need for an effective monitoring and evaluation framework to analyze impact and effectiveness of existing and future policies and practices.
In addition, there is a need for an increased exchange of experiences and best practices between governments, as well as a coordinated approach of the different initiatives organized by a growing number of organizations, with a view to avoid overlapping.

The foreign fighters topic will stay with us for many years to come. It is therefore of the utmost importance to quickly deepen our knowledge of the root causes of this phenomenon and to take adequate responses accordingly to bring results in the long term. This should be done in the above-mentioned order, i.e. focusing first on the root causes and then on the responses. The current responses sometimes appear to point to a lack of strategy and understanding, and also their necessity and effectiveness is not always clear. Although it is quite understandable that politicians will adopt as many measures as possible, in the hope of not getting the reproach afterwards by their constituents of not having done enough to thwart an attack, we should continue to strive for necessary, proportionate, sustainable and international law and human rights-respecting responses only.

The author

Christophe Paulussen is a senior researcher international humanitarian law/international criminal law and coordinator of the Public International Law cluster at the T.M.C. Asser Instituut in The Hague. In addition, he is research fellow at the International Centre for Counter-Terrorism – The Hague (ICCT). The T.M.C. Asser Instituut is a foundation with the purpose of performing and maintaining scientific research and education in the areas of international and European law and the ICCT is an independent think tank and knowledge hub that focuses on information creation, collation and dissemination pertaining to the preventative and international legal aspects of counter-terrorism.

1 This article is based on Ch. Paulussen, ‘Responding to Foreign Fighters: A Quick Overview for People with Little Time’, ICCT Commentary, 21 April 2015, available at: (last accessed 13 June 2015).

2 See ‘Addressing the Foreign Terrorist Fighters Phenomenon from a European Union Perspective: UN Security Council Resolution 2178, Legal Issues, and Challenges and Opportunities for EU Foreign Security and Development Policy’, Global Center on Cooperative Security, Human Security Collective and International Centre for Counter-Terrorism – The Hague, December 2014, available at: accessed 21 April 2015), p. 1.

3 Ibid.

4 See P.R. Neumann, ‘Foreign fighter total in Syria/Iraq now exceeds 20,000; surpasses Afghanistan conflict in the 1980s’, ICSR, 26 January 2015, available at: (last accessed 21 April 2015).

5 Ibid.

6 Council of Europe, Parliamentary Assembly, ‘Foreign Fighters in Syria’, Motion for a resolution tabled by Mr Dirk Van der MAELEN and other members of the Assembly, Doc. 13559, 30 June 2014, available at: (last accessed 21 April 2015).

7 See P.R. Neumann, ‘Foreign fighter total in Syria/Iraq now exceeds 20,000; surpasses Afghanistan conflict in the 1980s’, ICSR, 26 January 2015, available at: (last accessed 21 April 2015).

8 Ibid.

9 United Nations Security Council, S/RES/2178 (2014), 24 September 2014, available at: (last accessed 21 April 2015).

10 See ‘Addressing the Foreign Terrorist Fighters Phenomenon from a European Union Perspective: UN Security Council Resolution 2178, Legal Issues, and Challenges and Opportunities for EU Foreign Security and Development Policy’, Global Center on Cooperative Security, Human Security Collective and International Centre for Counter-Terrorism – The Hague, December 2014, available at: (last accessed 21 April 2015), p. 10.

11 See E. Bakker, Ch. Paulussen and E. Entenmann, ‘Dealing with European Foreign Fighters in Syria: Governance Challenges & Legal Implications’, ICCT Research Paper, 16 December 2013, available at: (last accessed 21 April 2015), p. 4.

12 See ‘Nigeria’s Boko Haram pledges allegiance to Islamic State’, BBC, 7 March 2015, available at: (last accessed 21 April 2015).

13 See also M. Singleton, ‘Paris 7-8 January: Darkness in the City of Light’, ICCT Op-Ed, 9 January 2015, available at: (last accessed 13 June 2015): “Empirical data indicates that the perceived legitimacy of counter-terrorism policies is the primary factor shaping the willingness of Muslim communities in the US and the UK to support and help. Aggressive counter-terrorism policies, on the other hand, have had the effect of alienating Muslim communities everywhere. We should never allow the attacks in Paris on civil rights and liberties to open up another Pandora’s box of draconian measures that, in the end, only serve to limit the foundations of our societies and render us more vulnerable.”