I. Phenomenon of foreign fighters
Various definitions and understandings exist on who is a foreign fighter,4 but in essence a foreign fighter is an individual who leaves his or her country of origin or habitual residence to join a non-state armed group in an armed conflict abroad and who is primarily motivated by ideology, religion, or kinship, not material or financial gain.5 In other words, foreign fighters are different from mercenaries because their primary motivations are not financial or material.6 This definition comes with a major caveat: From an international humanitarian law perspective, the term fighter may be a misnomer: under international humanitarian law, persons commonly referred to as ‘fighters’ are covered by a series of terms of art, such as members of dissident armed groups or other organized armed groups,7 or persons who take direct part in hostilities,8 and civilians who take direct part in hostilities.9 Persons who assume exclusively non-combat functions, such as for example administrative, political or propaganda functions, do not directly participate in hostilities under international humanitarian law.10 In other words, one would need to know much more about the role and functions of ‘foreign fighters’ to be able to confirm that they are indeed fighters in the sense of directly participating in hostilities.
Foreign fighters are not a new phenomenon: One of the largest foreign fighter mobilizations of the 20th century took place during the Spanish civil war with foreign volunteers fighting with the International Brigades and a much smaller number of foreigners joining Nationalist factions.11 Yet nowadays, foreign fighters as a phenomenon are mainly associated with conflicts in the Muslim world: since the first major Muslim foreign fighter mobilization for post-Soviet invasion Afghanistan, foreign fighters have been a salient feature of virtually all conflicts in the Muslim world.12 Empirical research on foreign fighter mobilizations across conflicts is limited, mainly due to the scarcity and unreliability of the available open source data.13 Nonetheless, some tentative conclusions may be drawn from the available research. First, foreign fighter mobilizations for conflicts taking place in the Muslim world are largely an Arab and North African phenomenon with only a small proportion of foreign fighters from the West.14 Second, many different push and pull factors play a role in the mobilization of foreign fighters and their relative weight varies across conflicts and countries of origin. Yet, the available data suggests that before the current foreign fighter mobilization for Syria and Iraq, foreign fighter mobilizations have always peaked when non-Muslim countries intervened in Muslim countries with force.15 Third, when it comes to recruitment, former or active foreign fighters play an important role, which explains why large numbers of foreign fighters tend to exacerbate foreign fighter mobilizations.16 Today, social media play an increasingly important role in the recruitment of foreign fighters, in particular Western foreign fighters.17 Finally, despite the difficulties in assessing the impact of foreign fighters on local insurgencies, existing studies have shown that the influx of foreign fighters tends to prolong armed conflict, renders them more intractable, and contributes to a radicalization of tactics and ideology.18 At the same time, their influence should not be overstated in the sense that the overall number of foreign fighters only accounts for a relatively small percentage of the total numbers of fighters in an armed conflict.19
1. The foreign fighter mobilization for Syria and Iraq
The current foreign fighter mobilization for Syria and Iraq stands out for a number of reasons, both in terms of quantity and quality.
Quantitatively, the current foreign fighter mobilization took place at an unprecedented pace and is of an unprecedented scale and breadth of geographic origin. In its May 2015 report, the Analytical Support and Sanctions Monitoring Team to the Al-Qaeda Sanctions Committee reported that were more than 20,000 foreign fighters from over a 100 countries active in Syria and Iraq, including approximately 4,000 from Western countries.20 With these numbers, there are more foreign fighters active at the same time in Syria and Iraq than in any other previous conflict,21 and there are more European foreign fighters than during all the armed conflicts of the last twenty years combined.22 As far as we know, most foreign fighters join the al-Qaeda breakaway group that calls itself the Islamic State (IS),23 but other groups such as the official Syrian al-Qaeda off shot Jabhat al-Nusra, Ahrar al-Sham and the free Syrian Army have also attracted foreign fighters.24 However, the proclamation of the caliphate at the end of June 2014 further increased the appeal of IS and the large majority of European foreign fighters are reportedly joining it.25
In terms of quality, it is hardly surprising that with such a large number, there is no clear profile of a typical foreign fighter: foreign fighters include both men and women from a range of socio-economic, educational, professional and ethnic background, and across a wide age range.26 The relative proportion of individuals coming from a particular group may vary across countries. Similarly, their motivations are varied and mixed. Some are seeking to belong or gain acceptance, sometimes coupled with a feeling of disenchantment or alienation in their home countries; or they are looking for adventures or go for humanitarian reasons. Others are drawn to jihad and looking for combat.27 Nonetheless, some common features are discernable among the foreign fighters, features which also set them apart from previous foreign fighter mobilizations: Today foreign fighters tend to be young, in their late teens or early twenties. Most did not have any previous association with violent extremism or showed a particular interest in religion or politics. Instead, their departure is often perceived as sudden rather than the result of a protracted radicalisation process As a result, their religious, political and geopolitical understanding tends to be very superficial.28
Finally, the picture of foreign fighters in Syria and Iraq has become more complex during the recent months as reportedly Westerners have been joining Kurdish militia to fight against IS.29
2. Linkages between foreign fighters and terrorism
As explained above, foreign fighters tend to have a negative influence in an armed conflict. However, their countries of origin are much more concerned about the linkages between foreign fighting and terrorism. The foreign fighter mobilization for post-Soviet invasion Afghanistan spawned al-Qaeda and like-minded groups across the world and foreign fighter mobilizations serve as an important recruitment tool.30 The fear is that trained foreign fighters, experienced in handling weapons and explosives, may plan and carry out terrorist acts upon return to their home countries, or set up new terrorist cells, recruit new members, or provide funds for terrorist acts and movements. Most foreign fighters never get involved in acts of terrorism outside an armed conflict zone.31 In his systematic cross-conflict study, Thomas Hegghammer concluded that ‘no more than one in nine foreign fighters returned to perpetrate attacks in the West.’32 Yet, this blowback rate is an average that cannot be extrapolated and used for all conflicts: The rate for a given conflict can be higher or lower, depending on a series of factors, including whether Western states are intervening in the conflict or whether the armed groups on the ground have a strategy that includes targeting Western countries.33 The ‘no more than one in nine’ rate would not only ‘make the foreign fighter experience one of the strongest predictors of individual involvement in domestic operations that we know’,34 but the involvement of returning foreign fighters significantly increases the likelihood and lethality of a successful terrorism plot.35
II. Foreign Fighters under international law: the ‘foreign terrorist fighter’
Not surprisingly, the question how to prevent and suppress the flow of foreign fighters to Syria and Iraq led to a legislative activism on both the national and international level. Most importantly, the Security Council adopted two resolutions on so-called ‘foreign terrorist fighters’.36 In addition to setting out measures to cut the financial resources of IS and other groups associated with al-Qaeda in Syria and Iraq,37 Security Council Resolution 217038 condemns the recruitment of ‘foreign terrorist fighters’ by IS, al-Nusra and other entities associated with al-Qaida; and requires States to take measures to suppress their recruitment. Yet, Resolution 2170 was limited to ‘foreign terrorist fighters’ of IS, al-Nusra and other entities associated with al-Qaeda. In contrast, Security Council resolution 2178 is broader in scope: adopted under Chapter VII, Security Council Resolution 2178 is not limited to a particular situation or group and imposes general obligations to prevent the movement of ‘foreign terrorist fighters’, defined as ‘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’.39 In order to suppress and prevent the flow of such ‘foreign terrorist fighters, states are required, amongst others, to adopt the necessary legislation to prosecute their nationals and other individuals who travel abroad to perpetrate or participate in terrorist acts, including to provide or receive training; the financing of such travel; and the organization or other facilitation of such travel, including recruitment of ‘foreign terrorist fighters’.40 Two aspects of the resolution deserve further comment. First, the Resolution introduces new terrorism related offenses beyond what is provided for in any universal treaty and without providing a definition of terrorism. Second, the scope of the concept of ‘foreign terrorist fighter’ remains vague and ambiguous.
1. New terrorism-related offenses
Security Council resolution 2178 requires States to criminalize a series of terrorism-related activities that were not previously criminalized in any universal international instrument governing the prevention and suppression of terrorism. First, Security Council resolution 2178 includes ‘providing or receiving terrorist training’ and ‘recruitment’ as prohibited acts. Security Council Resolutions 1373 called on states to suppress recruitment, but abstained from requiring states to make such recruitment a criminal offence.41 Article 3 of the EU framework decision to combat terrorism was amended in 2008 to include recruitment and providing terrorist training, but not receiving terrorist training.42 Finally, before the adoption of Resolution 2178, no other international instrument, whether universal or regional, included travel, or attempted travel, to engage in terrorist acts or terrorist training as a criminal offence, although such conduct may fall under broad material support statutes or preparatory act to engage in terrorism in some national legislations.43 The conduct criminalized thus includes a wide range of behaviour that is quite removed from the core crime, i.e. an act of terrorism.44
2. Who is a ‘foreign terrorist fighter’?
The term ‘foreign terrorist fighter’ and the measures to be taken, including criminalization of their travel, remains open in scope and will ultimately depend on national legislation.
First, the term ‘foreign’ conveys the idea that these are individuals who travel abroad to a state other than their state of nationality or residence. However, the interplay between the two notions is not clear, in particular in light of the situation of members of the diaspora and dual citizens who may be travelling from their state of residency to their state of nationality or vice versa. Whether or not such individuals would be covered, will ultimately depend on implementing national legislation.45
Second, the old problem of the definition of terrorism and ‘terrorist’ resurfaces: Security Council Resolution 2178 generically refers to ‘terrorism’, ‘terrorists’, ‘terrorist acts’, and ‘terrorist training,’ yet does not provide a definition of terrorism nor limit its reach to international terrorism.46 Although Resolution 2178 includes an explicit human rights safeguard clause,47 setting out such far-reaching obligations without defining ‘terrorism’ carries a significant risk of abuse48 ‘Foreign terrorist fighters’ are described as people who travel abroad, a routine activity for many people, but with a ‘terrorist’ intent. Yet, it is unclear how one is to distinguish a person who travels abroad for legitimate purposes from a person who travels abroad with a terrorist purpose without resorting to ethnic profiling.49 The implementation of Security Council Resolution 2178 may lead to de facto prohibitions to travel to certain countries and their neighbours.50 This is indeed the approach taken by the Australian ‘Foreign Fighter Bill’ which makes it an offence to enter or stay in an area of a foreign country that is declared as an area where a listed terrorist organization is engaging in hostile activity.51
Adopted against the background of the on-going foreign fighter mobilization for Syria and Iraq, the intended effect52 of the Resolution is to criminalize travelling or attempting to travel abroad to join armed groups that are considered ‘terrorist.’ In doing so, the Resolution unreflectively extends the concepts of ‘terrorism’ to situations of armed conflict,53 without considering the fundamental differences between terrorism and armed conflict, and the legal consequences flowing therefrom.54 Instead, the Resolution apparently presumes that engaging in acts of violence during an armed conflict abroad amounts to a terrorist offense,55 at least when fighting with certain groups. While this has often been the position under national law, so far this has not been the case under international law: Pursuant to the principle of belligerent equality, all parties to a conflict, have the same rights and obligations under international law. If the international framework to prevent and suppress terrorism were to criminalize mere participation in an armed conflict, at least with certain armed groups, as a terrorist-related offense, the principle of belligerent equality would be undermined. All international conventions and protocols on specific acts of terrorism that may occur during an armed conflict include a clause excluding acts governed by international humanitarian law.56 The question whether and to what extent acts by armed groups may constitute acts of terrorism continues to be an obstacle for the adoption of a comprehensive convention on terrorism.57 A possible solution to limit the effect of Security Council Resolution 2178 would be to limit the reference to acts of terrorism, including in connection with an armed conflict as referring to acts that are prohibited under international humanitarian law. Without expressly labelling them as such, international humanitarian law prohibits all acts normally designated as ‘terrorist’ if committed outside an armed conflict.58 Yet, it would be very difficult to prove that a person is travelling abroad to join an armed group with the purpose of committing such acts. Instead, the decisive criterion seems to be which groups foreign fighters are joining or intending to join: joining or attempting to join groups that are labelled as ‘terrorist’ becomes an offence in itself. Yet, which groups qualify as ‘terrorist’ groups? The Resolution expressly refers to ‘foreign terrorist fighters’ recruited by IS, al-Nusra, and other al-Qaeda associates listed under the 1267 sanctions regime. Hence, the Resolution requires states to, at the very least, criminalize travelling or attempted travelling abroad to join any of these listed groups as well as recruitment for such groups. Yet, the obligations in the Resolution are not limited to fighters of such groups.59 Other groups not listed as al-Qaeda associates under the 1267 sanctions regime may be included, depending on the respective state’s understanding of who is a ‘terrorist’ group. For example, some Kurdish militia fighting against IS in Iraq have ties to the Turkish PKK, which is still on the EU list of terrorist groups60 and the list of individual states, like the UK. Individuals fighting with such groups may thus also be covered by the term ‘foreign terrorist fighter.’61
III. Foreign fighters under national law
Although most national legislations do not criminalize fighting with a non-state armed group abroad per se, under national law foreign fighters may face criminal charges for their participation in hostilities abroad by two main avenues. First, foreign fighters may be investigated and prosecuted for ordinary crimes under national law even for acts that do not violate international humanitarian law, such as murder, arson or attempts to commit such crimes.62 Second, foreign fighters who join or otherwise associate with armed groups that are designated terrorist groups may be investigated on the basis of domestic terrorism legislation. Even before the adoption of Resolution 2178, domestic terrorism legislation already prohibited travel or attempts to travel abroad to join a ‘terrorist group’ under material support statutes or broad notions of preparatory act to engage in terrorism.63 Against the background of the foreign fighter mobilization of Syria and Iraq, some states have recently amended their domestic terrorism legislation to broaden their extraterritorial reach. For example, in December 2012 France amended its legislation to introduce the extraterritorial reach of the French terrorist offences not only on the basis of the active nationality principle, but also for individuals who reside in France.64 Similarly, the British 2015 Serious Crime Act extended the extraterritorial reach of the 2006 Terrorism Act to cover preparatory acts and training abroad.65
In addition to criminal law measures, many countries have amended or are in the process of amending their legislation in order to prevent foreign fighters from leaving, but increasingly also to prevent them from returning. First, many states have amended their legislation to broaden their powers to suspend or cancel travel documents, for example Australia66 and Malaysia.67 Second, states have also recently passed legislation to provide for broader powers to revoke citizenship of dual nationals, such as Canada in June 2014,68 or are debating legislation to this effect.69 Under the current British regime, the citizenship of naturalized mono-nationals may be revoked70 and the 2015 Counter-Terrorism and Security Act goes one step further by providing for a system of temporary exclusion orders prohibiting British citizens or persons who have the right to reside in the United Kingdom to return if the Secretary of State ‘reasonably suspects that the individual is, or has been, involved in terrorism-related activity outside the United Kingdom’ and that it is necessary to protect the public in the United Kingdom from a threat of terrorism.71 Such measures to limit the freedom of movement of suspected foreign fighters may not only fall short of states’ human rights obligations,72 but are also incompatible with states’ obligation to cooperate to prevent the flow of ‘foreign terrorist fighters’ under Security Council Resolution 2178 when used to prevent the return of suspected foreign fighters.73
IV. The way forward?
The response to the foreign fighter mobilization for Syria and Iraq has so far focused on curtailing the phenomenon from a security perspective with a heavy emphasis on repressive and coercive measures, although there are some notable exceptions such as the Danish Aarhus model to reintegrate and rehabilitate genuinely repentant and disillusioned returnees.74 The Security Council Counter-Terrorism Committee identified the lack of effective strategies and programs for the rehabilitation and reintegration of returning foreign fighters as a gap that may hinder the effective implementation of Security Council resolution 2178.75 In particular for young foreign fighters under the age of 18, more attention should be paid to their reintegration and rehabilitation upon return as they are not only potential perpetrators of crimes, but also victims of human rights abuses because human rights law prohibits the recruitment, voluntary and compulsory, of children under the age of 18 by non-state armed groups.76 Preventing minors from travelling abroad could also be framed as a protection rather than a security issue; particularly because minors are specifically targeted by IS and associate groups to travel abroad.77 Gendered assumptions about the motivations of young men and young women to travel abroad and their respective roles in IS and associate groups carry the risk that young men are primarily viewed as perpetrators of crimes to be punished upon return while young women are considered victims. From a preventive perspective, returning foreign fighters may play an important role in counter-narratives to dissuade others from leaving. Yet, facing draconian punishment under terrorism legislation, there is little legal incentive for them to come forward.78 Moreover, an overly repressive approach risks cancelling out parallel preventive approaches: fearing prosecution, family members and friends of suspected outgoing foreign fighters might be reluctant to contact the authorities, in particular in countries where attempted travel falls under domestic terrorism statutes. Security Council resolution 2178 requires criminalization of such travel or attempted travel, Yet, the reason behind the criminalization is less clear: whose interests are to be protected? The national security interest of the home state on account of the linkages between foreign fighting and terrorism? Or is the aim to protect the state of destination and its population from armed violence by foreign fighters? Is foreign fighting to be criminalized or only foreign fighting with certain non-state armed groups? And if so, on what grounds? The current foreign fighting mobilization for Syria and Iraq is mainly framed from a counter-terrorism perspective and as a security issue. Yet, the phenomenon, and any response thereto, must be contextualized: the dynamics of an on-going armed conflict influences foreign fighter mobilization. In the case of Syria and Iraq, the atrocities committed by the Assad regime or Shia militia play a role in recruitment narratives. Ignoring or downplaying them may further increase the appeal of groups such as IS. Ultimately, foreign fighter mobilization is likely to continue to some degree until a solution to the conflict is found.