On August 3, 2016, Jordan MacTaggart, a self-described radical leftist and atheist, was killed in action while fighting with a Kurdish militia against the Islamic State. It was his second tour of duty in Syria. McTaggart was seriously wounded during his first. Born and raised in suburban Colorado, he was a high school dropout, a reformed drug user, and a fan of punk rock. MacTaggart followed the conflict in Syria, discovered the Kurdish People’s Protection Unit, or YPG, and decided that fighting with them was worthwhile and a welcome break from his mundane life. MacTaggart was the second American killed fighting the Islamic State this summer and the third overall. With over 100 U.S. citizens estimated to have traveled to Syria and Iraq to join the fight against the Islamic State, stories like MacTaggart’s raise an important question: Why do individuals volunteer to fight in a war with which they have no connection?

When we began our research, which we presented at the Midwest Political Science Association’s annual meeting this past spring, we encountered a fundamental challenge. Most of academia and the media did not consider or call these (mostly) men fighting against the Islamic State “foreign fighters,” which they obviously are. In previous research, they were mostly ignored, and in the press, they were almost invariably referred to as “volunteers” or “vigilantes,” but they seemed more like foreign fighters to us, even if they were on the other side of the war. The most widely used definition of “foreign fighter,” at least in the academic world, comes from David Malet’s exceptional book on the topic. The fundamental criteria for inclusion were that the individual was not a citizen of the state he was fighting in, that he was a volunteer and unpaid, and that he was not a government agent of any kind. This specifically disqualifies mercenaries, employees of private military companies, and people who volunteer for foreign militaries. This allows us to distinguish people who volunteer to fight in foreign wars for reasons other than money or other personal gain from those that chase wars for the monetary benefit.

However, Malet includes a restriction that these volunteers must join an insurgency. However, he softens this by maximally defining “insurgency” to include any irregular militia, straining the common usage. This in turn limits the defining of “foreign fighter” to those that join rebellions and not fighters that join pro-government, but still irregular — militias, no matter the technical definition used in Malet’s study. The 100 or so Americans like Jordan MacTaggart were vaguely defined, limiting what we know about them and what lessons we could learn from them.

If we consider them foreign fighters, and we do, we have much to learn about and from them. One aspect of this particular population, specifically those that are Americans, is that they are not violating any laws by fighting against the Islamic State. Here they differ from those that fight with the Islamic State, who break U.S. law by fighting with a group on the Department of State’s list of Foreign Terrorist Organizations. One reason the preponderance of these fighters have joined the YPG is because if they joined the Kurdistan Workers Party, or PKK, they would then be in violation of U.S. law. This might be cut and dried legally, but not politically: The YPG is considered by Turkey and most regional experts to be the Syrian affiliate of the PKK, although the U.S. government distinguishes between the two and indeed provides the YPG with considerable military support.

Setting aside how various states view this particular group, other countries have a more blanket approach to foreign fighting. For example, the United Kingdom has a law that makes foreign fighting illegal, but has not been enforced the law in nearly 100 years, while Australia has outlawed this activity entirely. The second important aspect of this population is that they have been, on the whole, more than willing to talk with reporters about their actions and rationales for volunteering.

We posit that we can use this group of individuals, with their willingness to discuss their legal activities, to learn more about the causes of why people become foreign fighters generally. For obvious reasons, there are serious limits to what researchers can glean from illicit foreign fighters, particularly with regard to their motivations for mobilization. Toward this purpose, we built a dataset of American foreign fighters combating the Islamic State purely from open sources. Believing that we captured information on roughly one-third of all foreign fighters, we found that on average they were over 30 years old and that 82 percent had served in the U.S. military (half of the whole sample had served in Iraq and 29 percent in Afghanistan during their military service). Here, these individuals differ from Islamic State foreign fighters in that the latter are generally younger and did not have military backgrounds.

What does this data tell us about the mechanisms that drove them to volunteer in a foreign conflict? From our sample, we found that one-third mobilized because they developed an affinity with the victims of the Islamic State’s violence, while others volunteered for a mixture of personal grievances (typically with their position in life), adventuring and search for increased social status, and ideology (mostly religious). We are especially interested in exploring the role of moral shock in causing people to dissociate from their own social group to then develop an affinity with a group of distant strangers.

We realize we are offering more questions than answers here, but our research is still in its early stages. As we wrap up the publication of this first tranche of research, we intend to explore the following hypotheses in follow-on projects: (1) Individuals that experience moral shock and identify with the aggrieved group will be more likely to seek to volunteer for fighting abroad. (2) Pathways for joining or volunteering against the Islamic State will be similar to those joining the Islamic State. (3) Younger recruits seek risk and status and, thus, are more likely to fight against a government than for it. (4) The illegality of becoming a foreign fighter has little to no effect on an individual’s decision to become a foreign fighter. If you have thoughts on these hypotheses, please do engage us on Twitter (handles below). Fully developing and investigating these through the use of American anti-Islamic State foreign fighter proxies has the potential to significantly improve our understanding of the complex mechanisms that drive people to fight for strangers in distant lands.

Jason Fritz is a senior editor at War on the Rocks. He is also a doctoral student in the Department of Justice, Law and Criminology at American University’s School of Public Affairs and a senior consultant at the Noetic Group. @JasonFritz1

Joseph Young is an Associate Professor at American University’s School of International Service and an Associate Professor and Department Chair of the Department of Justice, Law and Criminology at American University’s School of Public Affairs. He is also an editor and contributor to Political Violence @ a Glance Blog. @JosephKYoung

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