The scale of the foreign fighters who have joined militant groups in Syria and Iraq has produced tremendous concerns about “blowback” against their home countries. Four years after the Syrian Civil War began, there are now hundreds of volunteers who have returned to Western countries, and the potential prospect of many more in the years ahead.
Most of the fears, and justifications offered for stripping citizenship and barring their return, have been that foreign fighters have acquired battlefield training and global terror network connections that make them especially dangerous. They are also expected to be particularly effective at facilitating the radicalization of new recruits who may embarrass their countries as war criminals or return home as worse threats. Much of the surrounding debate has been about how to best counter a security challenge described as unprecedented.
However, if we move beyond our preoccupation with ISIS, there are actually a considerable number of precedents that we can examine for evidence about returned foreign fighters. In fact, after researching this phenomenon for ten years now, I can say that we have centuries of evidence from dozens of cohorts of foreign fighters. And there is consensus in the research indicating that extremely few foreign fighters appear to engage in militant activity after their returns, although obviously there are a few very famous counter-examples.
I would argue that the novel element to today’s foreign fighters is social media and how these have de-territorialized radicalization and recruitment. The difference with social media is that grooming foreign fighters no longer needs to occur in secretive meetings arranged in familiar locations by trusted contacts. It is foreign fighters who are currently over there, and their online support, who are the real-time sources of propaganda, and that is why returnees are likely even less instrumental to radicalization today.
Historical Patterns
Historically, we can document foreign fighters in close to 100 civil wars since the late 18th century. We don’t have precise data in even the biggest and best documented cases like the Spanish Civil War – which drew, in under three years, double the number that have recently gone to Syria and Iraq – but we can make a conservative estimate that there have been 100,000 foreign fighters worldwide over the past 250 years.
Despite their very different circumstances and ideologies, they are all strikingly consistent in the messages and processes by which they radicalized and mobilized, – messages of duty to a threatened transnational community – by their experiences in the field, – notably aggressive attacks, high fatality rates, and schisms with local fighters who tend to exploit them, – and by the fact that the overwhelming majority disengage from militant behavior upon their return, with a small percentage becoming involved in domestic terror networks or going on to other wars.
Throughout history, win or lose, foreign fighters simply went home and in many cases back to their old jobs. The so-called Arab Afghans of the 1980s were the first cohort of foreign fighters in modern history not to demobilize at the end of their war, but to continue for decades to hop to other conflicts and to train others.
It is too facile to explain the difference as the result of greater fanaticism or being more dangerous. Other transnational jihadis in Central Asia, in Yemen, and in Sudan in prior decades dissipated. But the bulk of the Arab Afghans were not permitted to return to their home countries and became perpetual insurgents, wandering from one war zone to the next. This development should serve as a caution to proposals to render foreign fighters stateless. When Osama bin Laden’s passport was stripped, he simply relocated his radicalization efforts, and to the rest of the world he was still Saudi.
The Threat of Returned Jihadis
In the twenty-first century, the patterns appear to have remained consistent. Out of tens of thousands of jihadi foreign fighters in the last 35 years, there have been a handful of returnees whom we can identify as significant radicalizers of domestic terrorists and next generation foreign fighters. Abu Hamza al Masri here in London and Hambali of the Indonesian Jemaah Islaimiyah might be the most notable.
Clint Watts’ 2008 study of the Sinjar Records of foreign fighters in Iraq demonstrated that individual returned foreign fighters were effective in recruiting multiple individuals from particular communities in Arab countries like Libya. And this makes sense because returnees have the credibility and glamor to serve as exemplars, and the logistical connections to help others to get to the battlefield. But we do not have evidence about how many veterans foreign fighters do this, or whether it is representative of trends in Western countries as well.
Rather than radicalization, we see that returned foreign fighters in the West have been involved in facilitation, as they have been in Arab countries, but they are typically not the charismatic leaders around which militant groups organize. So it is important to be clear about what we mean by radicalization, and whether it means indoctrination or enabling those who are already radicalized.
The biggest concern about foreign fighters since the Syrian conflict began has been that they will return home and transition from being insurgents to being proficient terrorists. And there have been a dozen reported instances in Europe alone by returnees from Syria, most involving weapons possession and imminent plots. Others, such as the Charlie Hedbo attack, involved returnees who went elsewhere. But that case, and that of 7/7 bomber Mohammed Khan, involved individuals who trained with militant groups abroad but were not foreign fighters themselves.
Discussions of the threat of blowback frequently invoke Thomas Hegghammer’s 2013 article which indicated that up to around 10 percent of foreign fighters from the West were subsequently involved in terror plots, and that plots involving foreign fighters were more likely to be carried off and cause fatalities. But as Hegghammer notes, considering that we are not aware of everyone who becomes a foreign fighter, it is likely that a far smaller percentage of returnees become terrorists.
More recent studies have raised other measurement issues. Many of the terrorism-related arrests have been for minor charges such as possession of banned materials, or were possible entrapment cases where law enforcement arranged plots and looked for plotters. Jeanine De Roy van Zuijdewijn found that returned jihadis were involved in only about 10 percent of lethal terror attacks in the West. And a number of the returned foreign fighters had been on watch lists before they ever left, so it is not clear that they were radicalized abroad or would not have committed attacks anyway. But there is evidence that having promising fighters go off to Iraq depleted the talent pools of Saudi militants during the last decade, which was the same reason why the Comintern did not permit its young leadership in Britain to go to Spain in the 1930s.
It is important to recognize the impact of social media in this area too. We have evidence of disillusioned foreign fighters airing their grievances in letters to newspapers as far back as the 1830s. In the Twitter era, interested parties follow fighters while they are still in Iraq and Syria, and it matters less whether they physically return or not. Arguably, those who are still in the field will have far more interesting propaganda than someone who has returned to the everyday world.
Finally, we are witnessing a factor that was not documented in the past, and that is high rates of PTSD among returnees in rehabilitation programs in Western Europe and, as I have heard from colleagues in Indonesia, severely acute symptoms. Assuming that this too is an historical constant, it might explain why returnees have rarely been at the center of recruitment efforts, and that is simply that many do not survive and most of those who do had a very bad time in the field.
What to do about Returned Foreign Fighters
And this is the best tool governments have at their disposal to prevent radicalization, and why I argue it is a mistake to bar their return. We know that a very small percentage become domestic threats, but among those who do are the most effective and credible counter-radicalization spokespersons possible. In the United States, convicted drink drivers, even those responsible for homicides, are sent to schools to talk to students, and they offer more potent warnings than any public service announcement could. On balance then, returned foreign fighters are probably less of a threat to further radicalization that they are a resource for preventing it.