The post-9/11 wars have spurred a lot of attention on the problem of transnational foreign fighters. Such foreign fighters—foreign nationals drawn to intervene into civil conflicts for reasons of religion, ethnicity, or ideology—have been used to generate combat power on the ground and in many cases have been exceedingly brutal and indiscriminate in the application of violence. The present war in Syria has shown the deadly power of such fighters as have the battlefields of Iraq, Afghanistan, Somalia, Yemen, Libya, and other war zones. But this phenomenon is not new and is not simply an output of the Islamic faith. The Spanish Civil War (1936-39), for instance, had many foreign combatants drawn from the ranks of communists, socialists, and fascists. Even today, there have been signs in an uptick of white supremacists joining the ranks of the pro-Ukrainian and pro-Russian forces in Ukraine.

The Foreign Policy Research Institute has long had an interest in this topic dating back to conferences held in 2009, 2010, and 2011 (off the record) and many discussions and writings by our scholars (e.g., here, here, and here). To discuss the state of the foreign fighter problem and its future, the Program on National Security convened an online discussion, moderated by Program Director Michael P. Noonan, with its Senior Fellows Colin P. Clarke and Barak Mendelsohn and with R. Kim Cragin, the senior research fellow for counterterrorism at the National Defense University, and David Malet, Assistant Professor in the Department of Justice, Law & Criminology at American University.

Michael P. Noonan: First off, I wanted to thank each of you for agreeing to take part in this roundtable. All of us in the policy research and academic spheres know about the so-called “Chatham House Rule” about non-attribution, but less known about is what my friend Frank Hoffman refers to as the “Random House Rule.” The Random House Rule is the promotion of others’ writings! So before we get to questions I’d just like to refer everyone to Colin’s book After the Caliphate: The Islamic State & the Future Terrorist Diaspora, Barak’s book Jihadism Constrained: The Limits of Transnational Jihadism and What It Means for Counterterrorism, Kim’s book Women as Terrorists: Mothers, Recruiters, and Martyrs, and David’s excellent Foreign Fighters: Transnational Identity in Civil Conflicts.

With that out of the way. I’d like to start by asking everyone about their opinions on recent operations in Syria and the fate of ISIL foreign fighters and their families there. These fighters were being held by Kurdish forces, but whose fates are now in doubt due to Turkish military operations. This is further complicated with the news that Turkey might try to weaponize these fighters, many of whom are not allowed to return to their countries of origin, by giving them an open passage home. How does the role of foreign fighters in the Syrian conflict differ from earlier examples such as Iraq (2003-11) or Afghanistan (1979-1989, 2001-present)? How worried should we be about this situation?

Colin Clarke: I think the role of foreign fighters in Syria differs from previous conflicts like Iraq and Afghanistan in several important ways. The sheer magnitude or number of foreign fighters is much higher in Syria than it was in these other conflicts. The international community, and not just the West, should, of course, be concerned about foreign fighters attempting to return to their countries of origin to plot attacks, although I think the chances of this happening in the United States are close to nil. In Europe, the odds are slightly higher, but still low, especially given improvements in intelligence sharing and cooperation both within and between European Union countries, as well as advancements in biometrics and common databases. Countries like Indonesia have expressed grave concern in the weeks since jailbreaks have taken place, and countries in the developing world with less than robust border security and intelligence and security services are obviously at higher risk of returnees getting back into their countries surreptitiously to attempt an attack or link up with other militants already there. I think the most realistic threat is that foreign fighters who escape from detention centers will seek to remain in the region and connect with ISIS cells in Iraq and Syria.

Kim Cragin: Thank you, Mike, for pulling together this discussion. As you aptly describe, the current situation in Syria is precarious at best with a lot of flux. Strictly through the lens of foreign fighters, to me, three main concerns exist. First, foreign fighters from the West—either those in Kurdish prisons, camps for internally displaced persons, or elsewhere—may take the opportunity presented to them by the withdrawal of US forces to make their way home (undetected) and conduct terrorist attacks. Second, foreign fighters, not only from the West, but also other countries, may use those same opportunities to disperse to other conflict zones, such as Libya, Mali, the Philippines, or Afghanistan. Third, foreign fighters may reintegrate with the Islamic State, join clandestine cells in Syria and Iraq, and live to fight another day. 

Of these three, my most immediate concern is the latter. I believe that the Global Coalition Against the Islamic State/Daesh has done well to create an architecture, built largely on cooperation between the military and law enforcement, to reduce the threats posed by returning foreign fighters. But doing so has required significant resources, including intelligence, law enforcement, military, and diplomatic engagements. As time moves on, I am concerned that the attention and resources given to this issue will wane. Under those circumstances, especially if foreign fighters remain integral to Islamic State clandestine cells in Syria, I believe that the risk of external operations planned, financed, or executed by foreign fighters will increase once again.

David Malet: There is good news and bad news about the ISIL detainees: Based on patterns of past behavior, the current crop of foreign fighters is not likely to pose an acute domestic terrorism threat for very long, but the population of non-combatants and minors is unprecedented and unpredictable. There were more foreign fighters in the Russian and Chinese Civil Wars than there were in Syria, and the Communists in those conflicts also recruited Western civilian women and provided them with special shopping districts. But those were limited numbers, and there were not thousands of children to consider.

In a recent study, I found that few jihadi foreign fighters engage in domestic terrorism, and nearly all attempt it only within the first few months after they return. So even if the detainees escape or are released, we should only have a short-term threat. But we have no way to tell whether their children are truly radicalized and, if they are, what role they will attempt to play in the future. 

Barak Mendelsohn: There are several good reasons to be worried about foreign fighters. I want to emphasize four reasons: First, there are comparatively more foreign fighters than in earlier campaigns playing more central roles. Second, these individuals have even greater fighting experience. Third, many of them are motivated by ideological zeal to re-create the caliphate and establish Islam and Muslim dominance worldwide. And fourth, the appeal of transnational ideas, combined with technological developments, are enabling them to effectively act upon these ideas and to extend the scope of the threat.

The role of foreign fighters has expanded since the early days of the war against the Soviets in Afghanistan. Their share of the fighting force has significantly increased. During the 1980s, most foreign volunteers were engaged in facilitation work—primarily logistics, medical care, and media operations. Only a small number were actually involved in fighting, and their number was miniscule compared to the number of locals fighting. In the 1990s campaigns in Bosnia, Chechnya, and Kashmir, foreigners assumed more combat roles and demonstrated great combat effectiveness, but their number was still very small compared to the locals and their excesses tended to undermine the political objectives of the insurgencies they joined. But meaningful change came after the U.S. invaded Iraq in 2003. In Iraq, foreign fighters took center stage leading the fight against the U.S. and the Iraqi regime. In addition, foreign fighters transitioned from being an auxiliary force to shapers of a transnational political agenda: the Jordanian Abu Musab al-Zarqawi became the face of jihadi resistance in Iraq. When he joined forces with al-Qaeda in 2004, the transnational dimension of the conflict was further bolstered.

These tendencies only increased with the Islamic State, particularly after the announcement of its self-styled caliphate in 2014. Foreign volunteers account for a much greater share of the overall movement than any prior jihadi campaigns. Moreover, while the group was still led primarily by Iraqis, it worked to strengthen its transnational agenda with the “caliph” renouncing nationalism and claiming authority over all Muslims worldwide. Presenting a “positive” agenda—the restoration of the utopian caliphate—was different from earlier foreign mobilizations that underscored the need to assist fellow Muslims coming under attack. Indeed, when one looks at the motivation of foreign volunteers to join the fight in Syria and Iraq, it is evident that prior to the rise of ISIS and the announcement of the caliphate most volunteers wanted to help fellow Sunnis attacked by Bashar al Assad’s murderous forces. Whereas after the caliphate was announced, the motivation of volunteers seeking to participate was in building the caliphate and living in what they imagined would be a model Islamic society.

Technological developments are also central to the different nature of foreign fighting since ISIS emerged: during the 1980s, Abdallah Azzam published a journal and traveled himself or used emissaries to distribute hard copies. Today’s technology allows jihadis to reach any location and more effectively build audience interest and commitment. This is not unique to jihadism; technological developments have enhanced the ability of all kinds of transnational campaigns. 

Noonan: We’ve seen in the past that fragmentation is a concern with terrorist groups and their foreign fighter volunteers. ISIL emerged from al-Qaeda, for instance, and surely groups and volunteers will continue to shift to different groups and opportunities. How do you weigh this? Does such fragmentation reduce the capabilities of such groups or does it just multiply the possibilities for more violence?

Clarke: As I recently wrote in Foreign Policy with Amar Amarasingam, I believe that, especially given the death of Abu Bakr al-Baghdadi, we are likely to see affiliates and franchise groups asserting more independence and autonomy. Over time, this will inevitably lead to some fragmentation, which itself is somewhat of a double-edged sword. On the one hand, it’s better for the West not to have to face a monolithic entity that functions as a proto-state and is able to marshal the resources that ISIL could at its peak, which included the ability to plan and conduct spectacular operations in the West. But on the other hand, the fragmentation, atomization, and splintering mean more groups to deal with, many of which will likely focus on parochial concerns and never threaten the West, but some of which may ultimately metastasize and grow into formidable threats in their own right. 

Cragin: This question is tricky because history provides multiple contradictory examples. Generally speaking, my view is that “fragmentation” or the emergence of splinter groups is positive in the medium term. Fragmentation causes disillusionment and hurts morale. Beyond fragmentation, splinter groups must compete with each other for recruits, money, weapons, and other resources. Terrorist groups’ operational costs, therefore, increase as they fragment and splinter. Sometimes, this occurs due to infighting instigated by foreign fighters. Sometimes not. But, either way, I tend to view it as generally positive for counter-terrorism forces.

That said, under some circumstances, I do not believe that the potential benefit of fragmentation is worth the risk. Specifically, foreign fighters sometimes are “sent” to other countries to assist, or even to lead, local fighters. These foreign fighters bring with them new tactics, technologies, and a more global perspective. The introduction of these new methods and ideas can improve the capabilities of local fighters, cause them to alter their target-selection, and, therefore, increase the level of violence. For example, Jemaah Islamiyah, an al-Qaeda affiliate in Southeast Asia, sent trainers to the southern Philippines in the mid-2000s. They taught local fighters, among other techniques, how to build improvised explosive devices (IEDs) with pressure-activated switches to make them difficult for security forces to defuse. Abu Bakr al-Baghdadi, the former leader of the Islamic State, similarly sent Iraqi Abu Nabil al-Anbari (aka Wisam Abd al-Zubaydi) to Libya to lead a local affiliate. These types of more elite foreign fighters can create disgruntlement amongst local fighters. But I believe that the risks they pose—the transfer of skills, leadership, and the relationships they bring—far outweigh any potential benefits gained from internal disgruntlement.

Malet: Individual foreign fighters switched sides in Syria, sometimes multiple times, so it seems like most will join the group that they think is most effective rather than being bound by ideological differences. We’ve also seen that when foreign fighter groups arrive in new theaters and compete with local insurgents for manpower and resources. Internecine jihadi fighting is probably going to be due more to this kind of rivalry than ideological fragmentation within the movement.

Mendelsohn: Fragmentation and unifications are natural part of the life of armed non-state actors, and the jihadi movement is no different in that way. Fragmented movements make preventing terrorist attacks harder, but the trade-off is that they are poorly positioned to advance their “positive” political objectives; they can still be lethal and disruptive, but less able to meaningfully promote their political designs. Fragmentation might make thwarting attacks more complicated, similar to the difficulties states face in preventing lone-wolf attacks, the embodiment of decentralized violence.

Furthermore, the shifting alliances, fragmentation, and regular movement of individuals between groups may produce unique opportunities for states to penetrate these groups. Fragmentation also increases the ability of intelligence agencies to magnify conflict among jihadis and to turn them on each other. Whenever these actors are busy fighting each other, they have less time, resources, and ability to attack non-jihadi enemies.

Ultimately, we must recognize that the solution to the problem of jihadi terrorism will not come from destroying their organizations—although that would help, and we must do our best to make that happen. The end to jihadism will come from producing an extensive rejection of jihadi ideology and objectives. Jihadi groups may rise and fall, but the potential for violence is going to increase simply because there is a greater awareness that it is easy. (Just compare the way we see vehicles as a weapon these days as opposed to in the past. Running over people is far easier than building a car bomb). Jihadi groups can vary in their lethality, but they will continue to pose a challenge because their worldviews are threatening. 

Noonan: What other trends do you see in the Islamist foreign fighter phenomenon? Will the war in Syria beget more wars fueled by returning veterans such as those that fought in Algeria, the Balkans, the Caucasus, and the Arabian Peninsula after the Soviet-Afghan war? Will these veterans spur more international terrorism? What conflict zones, or potential conflict zones, might they turn to next?

Clarke: I see a continuation of more of the same, or in other words, I believe that Islamist foreign fighters will continue to play a significant role in future conflicts, although I doubt we’ll ever see mass mobilizations on the scale that we did with the Syrian civil war, primarily because many governments have put measures in place to prevent such an outflow again. I do think that other conflict zones will remain a magnet for foreign fighters, both veterans of previous conflicts like Syria, but also newer recruits that missed their opportunity or were too young to participate. Civil wars, insurgencies, and conflict zones in West Africa, Libya, the Philippines, and Afghanistan would be toward the top of my list in terms of areas of concern to be on the lookout for.

Cragin: The foreign fighters that travelled to Syria and Iraq to join the Islamic State served multiple functions. Yes, they returned home to execute terrorist attacks. But they also recruited new members, became involved in fundraising, and helped to orchestrate attacks back home. Much of this was done virtually. I expect the next generations of foreign fighters, based in conflict zones, to continue to find ways to exploit social media to pursue both local and international objectives.

As for the current generation of foreign fighters, for those still left in Syria, I expect that they will attempt to remain there. Others have already left. Some are in jail. Some were deported. Some simply have disappeared. I expect a majority of these to return to violence. In this context, the single largest population of foreign fighters—both those who travelled to Syria initially and those who have returned—are Tunisians. But, after multiple trips to the region, I am actually less concerned about Morocco-Tunisia-Algeria. These countries have identified the threat and shifted resources—intelligence, law enforcement, military—to respond accordingly.

I am more concerned about Libya-Egypt-Sudan. The Islamic State and al-Qaeda both have deep roots into these countries and, thus, it seems logical that foreign fighters will turn to these areas to re-group. The ongoing conflicts in Yemen, Mali, the Philippines, and Afghanistan also have attracted some foreign fighters, although to a lesser degree. That is not to argue that we should not be concerned about these conflicts, in general, but rather simply that they do not seem to be as attractive as Syria or Libya for foreign fighters.

Malet: I have just completed participating in a project examining jihadis who travel on to be “career foreign fighters” in multiple conflicts. It turns out that not only do many of them rise through the ranks from foot soldiers to emirs and commanders, but that they disseminate best practices to other groups as well. So we can expect foreign fighters who cut their teeth in Syria and escaped to lead other groups and provide them with critical experience. They’ll appear where networks are in place and jihadi fighting groups are already active.

Mendelsohn: The foreign fighters’ problem is not going away. While some former fighters might be rehabilitated, many cannot. Even reformed foreign fighters are likely to experience institutional harassment for years to come because countries and societies don’t trust them. Those who serve time might even come out from prison growing more dedicated to the cause because prisons in the Middle East, the West, and elsewhere, tend to be breeding grounds for extremists. Programs with greater potential for success require much greater resources, which states are unlikely to allocate. Many foreign fighters are still in detention camps in the Middle East, where they are likely to remain dependent on ISIS and thus keep their attachment to the group. In the midst of the mess in Syria, many will soon find themselves free, but with no real options but to return to fight. And with a new generation of ISIS kids, knowing no alternative to their jihadi upbringing and the steady diet of jihadi propaganda, the problem only gets worse.

These foreign fighters will go where they can. The instability of the Middle East promises not only attractive causes, but also opportunities to move around. As the Middle East state system is struggling with the emergence of flashpoints, they will inevitably attract rebels in search of a cause.

Other foreign fighters, motivated by revenge, are likely to seek to attack their home countries. Whether part of an organization or self-organized cells, they will provide headaches for states’ security services for years to come. The inability of many states that exported foreign fighters to figure out where their nationals are, and especially which fighters made their way back home, magnifies the problem. In the EU, open borders and multiple state authorities will continue to produce terrorism vulnerabilities.

Noonan: Lastly, what are your thoughts on trends such as the emergence of white supremacist foreign fighters? What other ideas or beliefs might fuel others to band together to wage transnational campaigns? Does the modern era of influence operations and the rapid transit of news and RUMINT (rumors intelligence) make it more likely that others might band together or be used as proxies to cause problems?

Clarke: As we wrote about in our research paper for The Soufan Center, we trace the evolution of white supremacist foreign fighters and examine the role that Ukraine has played as an emerging hub for this movement. In terms of what ideologies or grievances might motivate individuals or groups to engage in transnational acts of terrorism or political violence in the future, two issues come to mind. First, one could envision a future where a backlash against technology serves as a motivating factor, almost a Neo-Luddite ideology undergirded by a palpable sense of anger that technology, automation, artificial intelligence, machines, and robots are the source of societal ills, including taking away people’s jobs and thus their livelihoods. The other area is violence or the destruction of property motivated by a belief that politicians and governments are not doing enough to address climate change and as such, more drastic measures are necessary to bring attention to the cause. 

Cragin: I believe that we are just now starting to understand the potential use (or misuse) of social media by non-state actors to identify, radicalize, and recruit new members globally. White supremacists. Criminal gangs. Terrorist groups. I do not believe that I am an alarmist on this issue. I acknowledge that extremist groups still struggle somewhat to operationalize this potential. But the trends in so-called “inspired attacks,” especially in combination with those virtually planned, are worrisome. Have state actors grasped this potential? Will they attempt to manipulate and weaponize transnational movements? Most definitely.

Malet: A growing number of foreign fighters have returned and created their own private security companies. Malhama Tactical, a group of jihadis with Syrian experience who take payment in Bitcoin, has received some publicity. But there are also non-jihadi foreign fighters who have incorporated, and now they have contracts from the United States and Canadian governments. These include former YPG volunteers now delivering countering violent extremism (CVE) programs in Europe and medical facilities in Africa, and Christian volunteers who fought with ethnic rebels in Myanmar now doing development projects in Syria and lobbying for U.S. intervention. So, as we see more non-jihadi foreign fighter veterans, expect them to become a new type of private sector player in peacebuilding and politics around the world.

Mendelsohn: As I noted earlier, the increase in the appeal of foreign fighting is linked to developments that are hardly unique to the jihadi movement. People all over the world have been engaging in transnational campaigns. They have grown more aware of transnational causes and have the means to coordinate activities instantaneously and over long distances. Many such campaigns we are likely to find admirable, for example, transnational campaigns to save the environment. Foreign fighters represent more contentious campaigns, but they should be seen as a part of the same phenomenon. As the globe becomes smaller and people find shared causes irrespective of their geographical locations, we can expect some of these causes to be related to a perceived threats or injustices that will prompt some individuals to actively participate in conflicts that do not relate to their nation state. White supremacists are only one example; individuals also joined the Kurdish fight against ISIS, often to the cheers of their compatriots. And as long as the international community does not swiftly prohibit any fighting not as part of a recognized state’s armed forces, combating the foreign fighters’ problem is only going to become more complicated. 

Noonan: Colin, Kim, David, and Barak, thank you so much for taking part in this discussion. Your insights are excellent as usual. I am sure that others will feel the same about this important, if troubling, phenomenon.