Since the outbreak of the Syrian Civil War in 2012, international security and terrorism literature has labelled a rather old phenomenon with a novel term; foreign fighters. The discussion has been further complicated with the interchanging use of other words such as mercenaries, foreign terrorist fighters or foreign jihadi fighters. The panic caused by terror attacks perpetrated by returning foreign fighters or acts of violence committed by those in the war zone has led academics, policy makers, and counter terrorism experts to work on ways to prevent the mobilization of such foreign fighters. In such chaotic environments, historical examples and experiences are commonly dismissed or misrepresented.

Nir Arielli’s latest book From Byron to Bin Laden: A History of Foreign War Volunteers intervenes in this discussion and serves as a reminder of its historical depth. The book is divided into eight chapters and, as the title indicates, covers almost 250 years from Lord Byron’s death in 1824 to Osama Bin Laden’s in 2011. Arielli starts his book by questioning the important military history aspect of ‘foreigners’ in national armies. Despite the fact that today’s foreign fighters are seen as outsiders, fighting in a place where they don’t know the language or culture (or simply put “don’t belong”) the book starts by reminding the reader that in fact men and women have been leaving their communities to fight wars in distant countries since as early as the Crusades. However, perception started to change in the late eighteenth-century with regards to citizen’s responsibilities to their nation. Although many nation-states portray their wars of liberation and foundation as nationalistic struggles, it would be a mistake to ignore transnational aspects and the participation of foreigners in these conflicts. In this respect, foreign volunteering is a rather modern phenomenon with its roots in the American, French or Italian revolutions.

Instead of equating the issue with a certain ideology, the author aims to compare commonalities among the volunteers in wars over different time periods and geographies. While doing this, Arielli offers his own historical categorization of the subject: For him the first era of foreign war volunteering is Liberty vs. Tranny, which covers the period of nationalist struggles throughout the 19th century in Spanish America, Greece and Italy. The second is Left vs. Right, which started with the October Revolution in 1917 and during which volunteers aimed to assist or prevent a regime change. The final era includes the end of the Cold War, which followed the Soviet invasion of Afghanistan in 1979 and which Arielli has named the Clash of Civilizations (p. 39).

For Arielli, dividing this debate on motivational lines would be a challenge since it is nearly impossible to determine the exact reasons for one’s actions. Yet one common denominator for all these foreign volunteers was “their search for a sense of purpose and meaning” (p. 69). Additionally, instead of categorizing volunteers from an ideological perspective (Islamist, communist or far-right) the author introduces a new typology for foreign volunteers in relation to their states; self-appointed ambassadors, diaspora volunteers, cross-border volunteers and substitute-conflict volunteers.

Arielli then moves on to state attempts to prevent or control the flow of volunteers, a topic which is still a lively discussion in policy circles. Despite both national and international attempts having been initiated to control (rather than prevent) the flow of foreign volunteers, they have continued to find new ways to reach their goals. In chapters 6 and 7 the author poses and attempts to answer an important question; “Is the threat they pose really so great?” With regards to military capability and effectiveness there is little that foreign volunteers offer to the ongoing struggles. However, it is troublemakers who radicalize in the warzones which attract most of the attention. Arielli finishes his book by reminding the reader that foreign volunteering is not just a momentary adventure which affects only the participating individual, but that it also leaves a memory which is followed by future generations.

As a professor of international history, Arielli helps us understand different dynamics of a complex situation without falling into narrow ideological dichotomies. Since most people who fit into the category of foreign fighters don’t see fierce battles, the most important aspect of the book is its emphasis on the volunteering rather than merely focusing on the foreignness or fighting. This approach helps situate the phenomenon into the long tradition of war history instead of creating new research areas such as non-state actors. In this sense, Arielli avoids the trap of state-centric epistemology and this separates the book from more policy-oriented works on security or international terrorism which want to answer the question of how to stop these foreign fighter flows in the first place.

One potential weakness of the book is its relative lack of attention to the more recent wave of foreign volunteers, namely those who claim to fight in the name of Islam. The author focuses on the most popular cases such as the Soviet invasion of Afghanistan, or ISIS in Syria and Iraq but doesn’t go into further detail, which would help to show the similarities and interchangeable nature of this historical categorization with previous eras. For example, despite framing their call to arms in religious (Islamic) terms, the conflicts volunteers joined in the Clash of Civilization wave were also struggles for (a form of) independence from either Soviet, Russian, American or Ethiopian military interventions, or to show solidarity with the plight of Bosnians. In that sense they might easily also be categorized under the term Liberty against Tyranny.

To conclude, Arielli offers a historically sophisticated book for both general readers and researchers of war studies. His analysis of foreign war volunteering from Europe, as well as the Middle East, goes beyond a mere contribution to the current debate on the fate of foreign fighters who are perceived as threats by their governments. It also reminds students of political science and international relations that there is much more to the story of nation-state building as it transcends borders.