Article Review 155 on “Leaning on Legionnaires:  Why Modern States Recruit Foreign Soldiers.”11 min read

In “Leaning on Legionnaires,” Elizabeth M.F. Grasmeder offers a much needed overview of the recruiting of legionnaires over the last two hundred years across the world. Along with providing an original dataset on state policies to enlist foreigners in their armed forces, a novel theoretical framework to think about the drivers of legionnaires recruiting, and an insightful case study on Nazi Germany during World War II, the author challenges common wisdom and academic thought on some fundamental characteristics of the state army.

H-Diplo | ISSF Article Review 155

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Commissioning Editor: Seth Offenbach
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Elizabeth M.F. Grasmeder.  “Leaning on Legionnaires:  Why Modern States Recruit Foreign Soldiers.”  International Security 46:1 (2021):  147–195.  DOI:

Published by ISSF on 15 March 2022

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Review by Matteo C.M. Casiraghi, University of Warwick and University of Denver

In “Leaning on Legionnaires,” Elizabeth M.F. Grasmeder offers a much needed overview of the recruiting of legionnaires over the last two hundred years across the world. Along with providing an original dataset on state policies to enlist foreigners in their armed forces, a novel theoretical framework to think about the drivers of legionnaires recruiting, and an insightful case study on Nazi Germany during World War II, the author challenges common wisdom and academic thought on some fundamental characteristics of the state army.

Until fairly recently, the three interconnected factors of states as unitary actors, the national army, and the monopoly on the use of violence often trumped any other conception of the state and its armed forces in International Relations (IR) literature.[1] The main implication for civil-military relations studies was the interpretation of the state army as a monolith, where only national soldiers, who were loyal and patriotic, conducted wars abroad and contributed to enforce the state monopoly on the use of force at home.

Observing the ground-breaking changes that followed the end of the Cold War, such as the end of conscription in most Western countries and the privatization of military technological innovation, scholars started to analyse the diversity of new forms of military formats across the world.[2] Many studies showed how different non-state actors like mercenaries, private military and security companies, and pro-government militias often complemented and provided crucial support to the national armed forces.[3] Another strand of the literature centred the attention on how various state-actors, such as state security forces, at times helped or replaced the army in performing some military and security tasks.[4] Finally, scholars have investigated various degrees of diversity within the army itself. Indeed, militaries enlist members of ethnic minorities, women, and foreigners with varying intensities and employing divergent policies.[5]

These studies of contemporary armies inspired scholars to look back at different historical periods, demonstrating that throughout time states have consistently implemented policies to recruit individuals from different ethnic, national, or gender categories, and to complement their militaries with various non-state actors.[6] In this way, scholars have cast shadows on the long-term common wisdom that states build monolithic armies that are stacked with only national male soldiers. This is exactly where Grasmeder’s article enters the game, demonstrating the diffusion, importance, and associated dynamics of legionnaire recruiting.

The first important contribution of the article is to map state policies to recruit legionnaires in national armies across the world from 1815 to 2020. Examining 91 states and over 200 policies, this useful data collection testifies the importance of studying the reasons behind legionnaire recruiting, highlighting an interesting theoretical puzzle given the common wisdom that states should prefer national soldiers, who are supposedly more loyal, patriotic, and effective. Variation on such a non-autarkic approach to military recruiting, as the author calls it (p. 148), can be explained by two different sets of factors.

On the demand side, a growing intensity of external territorial threats should convince leaders to rely more consistently on foreigners to increase their military power. On the supply side, the severity of internal constraints regarding domestic recruiting, such as salient ethnic cleavages or civil-military labour trade-offs, should drive decision-makers to opt to recruit legionnaires for their military needs. The interaction between these supply-and-demand drivers represents a key contribution of the article, providing a clear theoretical framework to think about recruiting policies.

The framework is first tested against a large-N dataset, whereby the author shows how legionnaire recruiting policies are more common during conflict (demand-side argument) and how alternative explanations, for instance that legionnaires are more widely used by colonial powers, do not find much empirical support. Next, the author relies on a qualitative congruence test on major World War II powers to show that domestic constrains on citizens recruiting (supply-side argument) were a relevant factor that led states to enlist foreigners in their armies in the midst of the conflict.

Finally, the author offers a detailed and insightful discussion of legionnaire recruiting in Nazi Germany during World War II, a case study that seems particular appropriate given the intense Nazi rhetoric on the supposed loyalty, patriotism, and inherent value of the German citizen, who was specifically identified in self-proclaimed racial terms. Through a careful and effective analysis of a vast array of historical sources, the author shows how the German Army, which in 1939 was an exclusionary citizens’ force, gradually started to embed in its ranks foreigners from Western Europe, then enlarged the recruiting activity to Eastern Europeans, and in 1945 became a war-machine that deployed every non-German it could find.

Most importantly, the author convincingly demonstrates that increasingly severe domestic constraints, in particular civil-military labour trade-offs, and mounting external threats, from low-risk in 1940 to existential in 1945, guided Hitler and his entourage to more and more consistently recruit legionnaires. Although limited in its potential for generalizability, as every single case study is, the analysis of the Nazi experience effectively shows the relevance of the supply-and-demand argument provided by the author.

Furthermore, the discussion is particularly convincing in ruling out some potential alternative explanations for the recruiting of legionnaires. For instance, one could expect that states with colonial ties would massively recruit foreigners from their colonial territories, hence relying more intensely on foreign military manpower compared to non-colonial states. Against this expectation, the author effectively demonstrates how the Nazi Germany case does not support such prediction. Similarly, the case study shows how Nazi recruiting was not driven by the need of particular expertise or skills, an alternative theory that should explain exogenous military enlisting. Finally, the author also competently shows how such growing recruitment of non-German citizens was not explained by the Reich’s need to reduce the number of its citizens’ casualties.

Besides the useful contributions in terms of data collection and analysis, a novel theoretical framework, and the meticulous discussion of the case study, the article generates relevant implications for the literature on civil-military relations, security studies, and International Relations more broadly. For instance, as mentioned above, the worldwide diffusion of legionnaire recruiting policies demonstrates the diversity of approaches to the military format, hence further contributing to dismiss inaccurate depictions of a supposed monolithic and autarkic national army that emerged in the first half of the nineteenth century and still lives on. Second, the article casts doubt on established arguments in IR literature, such as the fact that democracies win wars more often than other regimes also because their citizens are imbued with national values and are hence more loyal and effective.[7] Finally, there are policy-relevant implications as well. For example, when leaders evaluate the potential military power of their adversaries, they should not dismiss the possibility of legionnaire recruitment, a factor that could influence the calculation of forces and power on a potential battlefield.

The article has a few small spaces for improvement that are worth pointing out, in particular in order to sketch some avenues for future research. First and most importantly, since the author decisively fosters the debate about the diversity of military format models, the article could have focused more on how legionnaires fit in such complex organizational forms. For instance, are foreigners enlisted only in low ranks in the military hierarchy? Are they usually recruited as small and large groups or as individuals? What is the relationship between legionnaire recruiting and that of other actors that complement and/or support the national army such as private military companies or pro-government militias? Building a more detailed dataset on legionnaire enlisting policies in terms of the characteristics of legionnaires and their relation with other sectors of the armed forces and government-linked non-state armed actors could open the possibility of more quantitative approaches to the study of organizational differences in the military format, something that the literature certainly needs.

Such considerations seem relevant not only to provide a more thorough description of the dynamics of military enlisting, but also to consider other potential explanations. For instance, the same factors that, following the author’s argument, should increase legionnaire recruiting may instead drive leaders to rely on alternative private, non-state military solutions to enhance their military power, a dynamic that would hence lead to less legionnaire recruiting. It is true, as the author correctly notes, that states have less control over security contractors (or pro-government militiamen), but that does not directly imply that the dynamics that should explain their recruiting substantially differ. Following this path, the author could have considered standard explanations that usually focus on state and non-state armed actors other than legionnaires.[8]

For example, the so-called ‘casualties-phobia’ as a factor that reduces states’ reliance on citizen soldiers, which is ruled out as a convincing explanation in the case of Nazi Germany, could be more decisive in more recently enacted policies of legionnaire recruiting given the importance of media attention and audience costs regarding warfare in the contemporary era.[9] From a similar point of view, although the case study is discussed in a thorough and effective way, the reader may perceive the need of a more recent case. Considering the profound changes in military and security strategic cultures and in the global dynamics of conflict after the end of the Cold War, one could expect that the reasons that explain legionnaire recruiting today may be significantly different from those of World War II.


Matteo C.M. Casiraghi is a Marie Skłodowska-Curie Global Fellow at the University of Warwick’s Department of Politics and International Studies and the University of Denver’s Sié Chéou-Kang Center for International Security and Diplomacy. His research interests focus on international norms, military operations, mercenaries, parliamentary debates, rhetorical political analysis, visual politics, and populism.

©2022 The Authors | Creative Commons Attribution-NonCommercial-NoDerivs 3.0 United States License



[1] James Fearon, Domestic Politics, Foreign Policy, and Theories of International Relations. Annual Review of Political Science 1:1 (1998): 289-313, DOI:; David A. Lake, The State and International Relations (June 28, 2007), SSRN:; Wendy Pearlman and Kathleen G. Cunningham, Nonstate Actors, Fragmentation, and Conflict Processes. Journal of Conflict Resolution 56:1 (2012): 3-15, DOI:  https://10.1177/0022002711429669.

[2] Classically, Samuel E. Finer defines the military format as the specific organization the armed forces, a broad category that includes elements such as whether conscription is enforced, the ration between volunteers and professional soldiers, the distribution of resources among the various branches, and the organization of the military hierarchy, among the others. See Samuel E. Finer “State and National-building in Europe: The Role of the Military,” in Charles Tilly, ed., The Formation of National States in Western Europe (Princeton: Princeton University Press, 1975): 84-163.

[3] Deborah Avant, The Market for Force: The Consequences of Privatizing Security (Cambridge: Cambridge University Press, 2005); Sabine C. Carey and Neil J. Mitchell, “Pro-Government Militias,” Annual Review of Political Science, 20:1 (2015): 127-147, DOI:

[4] Erica De Bruin, “Mapping Coercive Institutions: The State Security Forces Dataset, 1960–2010,” Journal of Peace Research 58:2 (2021): 315-325, DOI:

[5] Robert Egnell and Mayesha Alam eds., Women and Gender Perspective in the Military: An International Comparison (Washington, D.C.: Georgetown University Press, 2019). Jason Lyall, Divided Armies: Inequality & Battlefield Performance in Modern War (Princeton: Princeton University Press, 2020).

[6] Matteo C.M. Casiraghi, “Weak, Politicized, Absent: The Anti-mercenary Norm in Italy and the United Kingdom 1805-2017,” Journal of Global Security Studies 6:1 (2021): ogz076, DOI:; Gary W. Cox, Marketing Sovereign Promises: Monopoly Brokerage and the Growth of the English State (Cambridge: Cambridge University Press, 2016); David Parrott, The Business of War: Military Enterprise and Military Revolution in Early Modern Europe (Cambridge: Cambridge University Press, 2012).

[7] Håvard Hegre, “Democracy and Armed Conflict,” Journal of Peace Research 51:2 (2014): 159- 172, DOI:; Dan Reiter and Allan C. Stam III, “Democracy, War Initiation, and Victory,” American Political Science Review 92:2 (1998): 377-98, DOI:

[8] For example on private military companies: Eugenio Cusumano, “Bridging the Gap: Mobilisation Constraints and Contractor Support to US and UK Military Operations,” Journal of Strategic Studies 39:1 (2016): 94-119. DOI: 10.1080/01402390.2014.1003638; or on pro-government militias: Clionadh Raleigh and Roudabeh Kishi, “Hired Guns: Using Pro-Government Militias for Political Competition.” Terrorism and Political Violence 32:3 (2020): 582-603, DOI: 10.1080/09546553.2017.1388793

[9] See, for example, Deborah Avant and Lee Sigelman, “Private Security and Democracy: Lessons from the US in Iraq,” Security Studies 19:2 (2010): 230-265, DOI: Louis J. Klarevas, Christopher Gelpi, and Jason Reifler, “Casualties, Polls, and the Iraq War,” International Security 31:2 (2006): 186-198, DOI: