Why do modern states recruit legionnaires—foreigners who are neither citizens nor subjects of the country whose military they serve? Rather than exclusively enlist citizens for soldiers, for the past two centuries states have mobilized legionnaires to help wage offensives, project power abroad, and suppress dissent. A supply-and-demand argument explains why states recruit these troops, framing the choice to mobilize legionnaires as a function of political factors that constrain the government's leeway to recruit domestically and its perceptions about the territorial threats it faces externally. A multimethod approach evaluates these claims, first by examining an original dataset of legionnaire recruitment from 1815 to 2020, then by employing congruence tests across World War II participants, and finally by conducting a detailed review of a hard test case for the argument—Nazi Germany. The prevalence of states’ recruitment of legionnaires calls for a reevaluation of existing narratives about the development of modern militaries and provides new insights into how states balance among the competing imperatives of identity, norms, and security. Legionnaire recruitment also underscores the need to recalibrate existing methods of calculating net assessments and preparing for strategic surprise. Far from being bound to a state's citizenry or borders, the theory and evidence show how governments use legionnaires to buttress their military power and to engineer rapid changes in the quality and quantity of the soldiers that they field.

As Berlin fell and German troops deserted their posts, Adolf Hitler lamented on April 27, 1945, that “300 Frenchmen still have to help defend the Reich capital.”1 Far from unique, the soldiers of the 33rd Grenadier Division SS-Charlemagne were among hundreds of thousands of foreigners still serving in the German military at the end of World War II. Strikingly, most other combatants had similarly recruited tens and hundreds of thousands of foreigners to wage offensives, repel invasions, and sustain the war. Such practices are far from rare. My research shows that from 1815 to 2020, ninety-one states have implemented more than two hundred such policies to enlist soldiers whom I refer to as “legionnaires”—foreigners who are neither citizens nor subjects of the state whose military they serve.2 Why do states begin or expand policies to recruit these troops?3

Conventional wisdom maintains that modern states prefer to staff their militaries with their own citizens (or, in the days of empire, imperial subjects), viewing them as uniquely effective and loyal soldiers.4 After the French Revolution, states increasingly ceased to recruit foreigners. But as Hitler's lament underscores, and a wealth of evidence demonstrates, the conventional wisdom is mistaken. For two centuries, legionnaires have been a recurrent feature of modern militaries and conflicts globally. Moreover, legionnaires, and the states that recruit them, have significant contemporary relevance. As of 2021, thirty-one governments maintain legionnaire-recruitment policies, with India, Iran, Russia, and the United States among the states using legionnaires to guard borders, intervene abroad, or suppress dissent.5

Unlike mercenaries or contractors, who fight outside a state's military, legionnaires are members of its armed forces. They are a regular tool of modern warfare and have been mobilized by states of every regime type, population size, and colonial experience. Their recruitment demonstrates that states do not view military manpower in autarkic terms; instead, they routinely reach beyond their citizenries to buttress their military capabilities.

This article advances a supply-and-demand argument to explain why states begin or expand their recruitment of legionnaires, arguing that this choice is a function of political constraints on a government's ability to recruit domestically and its perceptions of external territorial threats. The dependent variable concerns whether or not states choose to supplement their citizen soldiery with foreign recruits. Specifically, I consider new legionnaire recruitment as having occurred when states initiate policies to enlist foreigners where no such policies previously existed, or when they expand an existing policy to recruit individuals from groups that had been previously excluded from legionnaire enlistment efforts.

The argument's supply-side variable concerns how easily a government judges that it can safely recruit its citizens. Although governments have vast legal and practical abilities to draw on their populations for soldiers, doing so can present political costs. I argue that four factors can amplify those costs to the degree that governments perceive additional citizen recruitment as presenting intolerable dangers: a proximate political threat from within the regime; a threat external to the regime but internal to the state; a risk resulting from salient ethnic or religious cleavages; or anticipated labor trade-offs from mobilizing civilian workers into military service. In the presence of one or more of these factors, governments may lack the political leeway to sufficiently expand their soldiery using citizens alone.

The argument's demand-side variable concerns the acuteness of the external territorial threats that a state perceives. When states view themselves as increasingly endangered, they seek more combat troops to ensure their security and territorial integrity, moving to close the gap between the soldiers they have and those they need. States can thus find themselves caught between competing imperatives: territorial threats that demand they raise more troops and domestic contexts that makes securing sufficient citizen-soldiers perilous. Because states cannot hold one source of danger constant, setting it aside to focus exclusively on the other, they must find policies that satisfy both imperatives at once. States recruit legionnaires for just this purpose—to close the gap between the combat troops they require and the citizen-soldiers they believe they can safely mobilize.

Legionnaires present a paradox for existing scholarship, which views citizens as a modern state's preferred source of recruits. In this narrative, the massive scale of citizen enlistment achieved in post-Revolutionary France meant that the demands of international competition drove other states globally to replicate this model.6 Such a force, motivated by patriotism and nationalism, would be uniquely positioned to fight effectively and reliably, even in the harshest combat conditions.7 Over time, governments ceased to tolerate the risks that foreign mercenaries presented, viewing their financial motivation, lack of ties to the state's cause, and position outside its institutions as rendering them a threat to the “idea that states ought to have a monopoly on … force.”8 So complete was this transformation that, as Janice Thomson explains, the modern army “is composed solely of citizen-soldiers and officers.”9

To be sure, scholars have not neglected the role of foreigners in modern war. A robust literature has examined how terrorists and insurgents recruit foreigners and why foreigners participate in conflicts abroad.10 Scholars also have examined states’ foreign recruitment practices historically, with a particular focus on the military recruitment of slaves in the Ottoman Empire and the Islamic world.11 Research on how states manage diversity in their militaries also has looked at states’ use of foreign recruits, albeit not as a primary focus.12 Still, much remains to be explained.

Two studies have examined discrete periods of states’ foreign recruitment, which, together, posit four explanations for this practice that present alternatives to my argument. First, Thomson identified eighteen twentieth-century cases in which governments recruited foreigners into standing armies. She attributes the majority of these cases “to only two factors—an imperial legacy or a temporary manpower shortage,” while asserting that, in another nine cases of ad hoc enlistment, foreigners were “recruited for their special expertise.”13 Second, Kolby Hanson and Erik Lin-Greenberg identified twenty-three states that recruited foreigners in this century and offered three explanations for the states’ policies: acquiring specialized skills, affirming international bonds, or importing military labor.14 In this last category, “states have simply too small a domestic population to fill security force ranks,” or they have sufficiently large populations but enlist foreigners to minimize citizen losses.15 Neither study, however, offers a comprehensive review of the practice or a complete explanation for why states recruit foreigners.

This article's study of legionnaire recruitment and why states pursue it makes three contributions to scholarship and policy. First, the article aims to overturn a conventional wisdom about what modern militaries look like. Scholarship has posited and accepted narratives on the development of modern armies, who staffs them, and how those militaries are used, without the benefit of comprehensive data about how prevalent legionnaire-enlistment policies have been. Absent these data, scholarly understanding of military manpower policies has been incomplete and inaccurate. If this conventional wisdom is mistaken, scholars must reexamine whether research on topics such as conflict initiation and military effectives has internalized this flawed premise.

Second, military manpower is a foundational component of national power more broadly, even in the most technologically advanced armies. Because states often reach beyond their citizenries to secure an essential military resource—combat personnel—legionnaires demonstrate how frequently a central component of national military power is, in fact, international. For states willing to transgress norms that armies should comprise only citizens, legionnaires enable governments to expand the pool of soldiers they can mobilize in pursuit of their national interests. The article thus adds to debates about how states balance among the competing demands of international norms, material considerations, and security policy.16

Third, my argument provides new insights into the role of identity and war. In recruiting legionnaires, states forgo the combat advantages that a citizen-soldier's identity and national loyalty are supposed to provide. The recruitment of legionnaires shows how a state's desire for those advantages is not absolute, but rather highly conditional. When national security or survival is at risk, states view manpower in increasingly utilitarian terms: they seek the numbers and the skillsets that they need, while the importance of a recruit's identity diminishes. Moreover, in certain situations, citizens may not even be a state's preferred recruits. Scholarship has already explored how governments that view their citizens as threats change their battlefield tactics and military organizational practices to manage these risks, even to the point of sacrificing effectiveness.17 In recruiting legionnaires, governments have found ways to mitigate or even avoid this trade-off.

The remainder of this article unfolds as follows. After further discussion of my definition of legionnaires, I present a theory that explains why governments initiate or expand their recruitment of these troops. After outlining my research design, I test my argument against three types of evidence. First, I present the findings of an original, large-N dataset of legionnaire recruitment from 1815 to 2020. Second, I conduct congruence tests across World War II participants, uncovering additional support for my claims. Finally, I use process tracing to test my theory against a hard case for my argument—Nazi Germany. After examining alternative arguments, I summarize my findings and outline my theory's theoretical and policy implications.

As stated earlier, legionnaires are uniformed personnel who serve in a state's armed forces, but who—at the time of their service—are neither citizens of that state nor, in the days of empire, subjects of the government in whose military they serve. Legionnaires’ core attributes are linked to their identity and organizational membership; recruits may come from abroad, or they may already reside in the polity whose military they later join. Fundamentally, legionnaires lack the attribute that governments normally use to delineate between “us” and “them”—citizenship. In the days of empire, governments also distinguished between noncitizens with whom they shared an identity and over whom they had control (i.e., colonial or imperial subjects) and other noncitizens.18 Although legionnaires lack these links, as members of a state's armed forces, in organizational terms, they are identical to its citizen and/or imperial troops.

How do legionnaires differ from other foreign military personnel? Unlike allied soldiers or foreign advisers, legionnaires serve only one chain of command—that of the state whose military they join. Conversely, allies rarely if ever relinquish command and control over their troops, meaning “forces participating in a multinational operation will always have at least two distinct chains of command: a national chain of command and a multinational chain of command.”19 Allied troops and advisers are always members of their home military and under the control of their home government; legionnaires have no such tether to their states of origin. But if competing chains of command distinguish legionnaires from allies, what differentiates them from contractors or mercenaries? Legionnaires are members of a state's security apparatus; mercenaries and contractors operate outside its institutions.20 As the U.S. military explains regarding the disconnect that this organizational arrangement causes, the “management of contractor activities is accomplished through the … contracting organization, not the chain of command. Commanders do not have direct control over contractors.”21

One attribute of my definition of legionnaires bears elaboration: it is agnostic on how foreigners enter military service, applying equally to foreigners who volunteer and those whom states conscript. This choice makes sense for two reasons. For one, it is consistent with states’ historical practices. To states that have recruited legionnaires, how these soldiers entered service was neither of primary importance nor a distinction that fundamentally differentiated one foreign recruit from another. This view likely arises from the historical prevalence of conscription to recruit citizens—presenting a second rationale. Whether a citizen volunteers or is drafted certainly affects a range of details, and states could understandably view volunteers as more committed than conscripts. Nonetheless, conceptually, whether a citizen enlists willingly or is drafted does not make them a different creature. From the perspective of the government, both volunteers and conscripts are soldiers—an assertion as true for citizen-troops as it is for legionnaires. Having elaborated on definitions, this study turns to explaining why states recruit these individuals.

I argue that policies to recruit combat troops are a function of how a state perceives its vulnerability to defeat in war. This perception is shaped by two variables that together affect a state's demand for combat power and its ability to mobilize its citizenry for troops: the severity of external territorial threats the state identifies and the domestic political constraints that limit its willingness to marshal citizens into service. Because states always have citizens in their militaries, the theory's dependent variable is the decision by states to implement a new legionnaire recruitment policy, which occurs either when states institute measures to enlist foreigners where no such measures previously existed, or when they revise and expand the parameters of an existing policy to mobilize foreigners previously excluded from recruitment.22 As the severity of external threats, domestic constraints, or both increases, the probability that states will implement new legionnaire recruitment policies rises (see table 1).

Table 1.
Expected Probabilities of New Legionnaire Recruitment
perceived external territorial threats
severity of constraints domestically high
very likely
somewhat likely
very likely
somewhat likely 
very likely
very likely
very likely 
perceived external territorial threats
severity of constraints domestically high
very likely
somewhat likely
very likely
somewhat likely 
very likely
very likely
very likely 

Based on different variable values, two mechanisms can spark new legionnaire recruitment. The first mechanism is a substitution effect: as a government perceives that drawing further troops from the citizenry presents untenable political risks, but that it needs more soldiers to fend off a territorial threat, legionnaires become a politically cost-effective and desirable alternative to citizen enlistees. Here, the state uses legionnaire recruits to close the gap between the troops it needs and the citizen-soldiers it believes it can mobilize without creating political risks at home. Alternatively, a second mechanism can emerge when a government's demand for combat troops becomes inelastic. In cases where a state perceives threats to its very survival, the government begins or expands its recruitment of legionnaires because it is willing to pay any political price for more troops.23 Here, the state uses foreigners as part of a strategy to maximize the military manpower, citizen and legionnaire alike, that it can deploy to the nation's defense.

My argument is limited in three respects. First, it explains why states initiate policies to recruit legionnaires, not why states terminate them. Second, it pertains to proactive legionnaire recruitment: when a state uses inducements to entice foreign volunteers, or uses force to conscript foreigners who are already within its borders, or both. The argument does not apply to situations in which states simply remove a barrier to foreigners’ ability to serve, but take no further action. Third, it does not explain states’ efforts to mobilize other forms of foreign manpower, such as allies or mercenaries.


Manpower considerations are a linchpin of a state's national security policy. Having enough soldiers—with the desired skills—at a bearable financial and sociopolitical cost is the starting point for a state's military planning, choice of tactics, and preparation for and selection into war. How do legionnaires affect this calculus, and what are their potential dangers and benefits?

The recruitment of legionnaires can carry risks. By definition, legionnaires lack preexisting ties to the states whose militaries they join. Inculcated with different social experiences and norms, they could be a jarring addition to the ranks—particularly when recruited in large numbers. Governments, then, must gauge whether legionnaires could present discipline or cohesion problems. If insufficiently vetted or managed, they could even pose security risks. Recruiting legionnaires also could create reputational costs. Domestic opponents could point to legionnaire recruitment as evidence that the government had lost confidence in its own citizenry. It also could send ambiguous signals internationally. Would rivals interpret legionnaire recruitment as an indicator of an enemy's military decline or even as a signal of hostile intent?

Nonetheless, recruiting legionnaires can have undeniable advantages compared to relying on citizens alone. If Otto von Clausewitz's boast that the levée en masse brought “the full weight of the nation” to bear in war is true, then states that recruit legionnaires can surpass even that formidable threshold.24 For governments that have mobilized tens or hundreds of thousands of legionnaires in their states’ darkest hours, foreign recruits can provide a desperately needed boost, enabling these states to escape defeat or shift the trajectory of a conflict. By answering the military's need for sheer numbers, legionnaires can help states sidestep some of the long-term economic or political ramifications associated with imposing or expanding a citizen draft.25 In other cases, legionnaires provide an expedited source of battle-tested or skilled soldiers.

Legionnaires also can have advantages relative to other types of foreign support. When governments seek aid from allies, receiving that help is by no means certain. Conversely, states can recruit legionnaires at any time and without outside consent. Legionnaires thus provide states an opportunity to acquire international aid, even when their allies’ formal assistance or intervention is not forthcoming. From the perspective of the recruiting states, legionnaires have other advantages over allies and contractors: the states that recruit them retain direct control through their own chains of command. These trade-offs only elevate the importance of understanding why states decide to recruit foreigners into service.


The first variable in my theory concerns the supply-side calculus of a state's recruitment efforts and the ease with which a government can draw on its domestic manpower supply—the citizenry—to meet its need for soldiers.26 Although states have vast legal and practical abilities to use their citizenries to staff their militaries, doing so can incur political costs and risks. In my argument, four factors can amplify these political costs and risks to the degree that governments view their abilities to sufficiently staff their militaries with citizens as constrained: (1) a proximate political threat from within the regime; (2) a threat external to the regime but internal to the state; (3) blowback resulting from salient ethnic or religious cleavages; or (4) labor trade-offs from putting citizen workers into uniform.

This supply-side variable can assume one of three values depending on how many of the factors described above a government faces at a given time. When none is present, the government has low constraints in being able to enlist soldiers from within the population—it has the widest political latitude for recruiting from the citizenry. When one of these factors is present, the government is moderately constrained. It has far less political leeway for enlisting citizens. Governments are highly constrained when two or more of these factors are present at the same time. In these situations, citizen enlistment can present a veritable political and security minefield. How could any of these factors convince governments that they face risks by putting more citizens into uniform?

Internal Regime Threats. Fears of threats from within the regime can dampen a government's desire to enlist citizens if its leader believes that doing so risks empowering a rival. When leaders preside over regimes composed of a diverse set of political actors, insiders may maintain independent networks of support across the citizenry, and, by extension, among would-be recruits. Leaders who fear a proximate rival must therefore consider to whom each additional citizen-recruit is loyal—the existing regime or the potential challenger. By recruiting citizens of suspect elite allegiance, leaders must ask whether their rivals could use citizen enlistees to mount a military-backed bid for power.27

External (Domestic) Regime Threats. Fears of a threat external to the regime but internal to the state—such as fears of an insurgency or a mass protest movement—also can constrain a government's desire to recruit citizens. If such a threat were to unfold, there could be practical obstacles to mobilizing new citizen recruits. For example, if the regime's opponents control territory, the recruiting apparatus may not be able to physically access citizens to enlist. But even without a manifest internal crisis—for example, years after a civil war or an insurgency ends—governments may not have fully reestablished an administrative or a military presence in formerly rebel-held areas. Governments also could face informational problems about which recruits are loyal, particularly if acute political or economic grievances among the population are unresolved. With suspicions about potential citizen-recruits, governments must consider whether new enlistees could be unenthusiastic and poorly execute their military duties, thereby diminishing military effectiveness. Governments may even fear that citizen-recruits could present tangible dangers, such as by seeking to mount insider attacks or by acquiring training for later use against the regime.

Salient Sectarian Cleavages. When leaders use ethnic or religious identity to distribute political power, recruitment is unavoidably politicized. In countries ruled by a sectarian minority, and where such cleavages lead to the repression of segments of the population, citizen recruitment can be hazardous for two reasons. First, the government may fear that arming and training citizens from marginalized constituencies could present problems in the future, including the possibility that they might one day be on opposite sides in a domestic conflict. This danger can be particularly acute when security institutions reproduce the repression that citizens from marginalized groups experience in civilian life.28 Conversely, simply overstaffing a military with a leader's coethnics or coreligionists presents its own risks. If the leader enlists too many of his supporters, he may shift the burdens of combat and casualties onto his constituents, thereby risking their continued backing or even causing a political rupture.

Labor Trade Offs. When a state experiences full employment or a rising demand for matériel, whether in anticipation of a conflict or during one, the government must consider how every citizen is used.29 Is he better employed in industry or on the front lines? If fielded in battle, the government gains a soldier; but if that citizen-recruit is taken from a factory, the government is simply exchanging one kind of shortage for another. When critical production requires technical skills, governments may have even less flexibility and exempt a portion of the citizen labor force from military service. In total wars, these trade-offs can be particularly salient given the sheer scope of states’ matériel needs.

The constraints that limit the leeway that a government perceives it has in mobilizing its citizenry—whether from fears of internal regime threats, external regime threats, sectarian cleavages, or labor trade-offs—help shape the supply-side of a government's manpower calculus. Depending on how many factors the government confronts, it will experience low, moderate, or high constraints in mobilizing citizens for military service. Governments that experience higher levels of constraint believe that expanding citizen enlistment will present greater political and even security risks. When the feared political price makes this manpower option prohibitively costly, governments are likely to view legionnaires as a desirable substitute.


The second variable in my theory arises from the degree of territorial threat that a state perceives it is facing externally. This demand-side variable comprises two elements: the kind of military threat that a state believes it is confronting, and its severity. In my theory, territorial concerns are the primary focus and serve as the lens through which a country conceives of its external environment: national (or imperial) boundaries—their expansion, contraction, and integrity—are the priority.

External territorial threats can assume a value of low severity, high severity, or existential severity at a given time. Conceptually, I define a state as perceiving a low territorial threat when it is not actively engaged in conventional hostilities with an external foe and does not anticipate a near-term outbreak, or when it is actively engaged in hostilities but assesses that it is reliably winning battlefield engagements. When states enjoy peace and anticipate its continuation, there is little or no need to expand the soldiery; they may even shrink their ranks. For states that are at war, but view themselves as being successful, the quality and quantity of the existing combat cadre seems equal to the task. There is little or no excess demand for troops.

Conversely, states that perceive a high territorial threat are actively engaged in hostilities and view their battlefield situation with a degree pessimism about their security or a conflict's trajectory. In this context, government officials evidence a growing sense of urgency, even panic, to shift their state's fortunes. States that perceive high threats externally experience sustained and recurrent losses, and they fear that the trajectory of battlefield engagements, and even the entire conflict, favors the enemy. The state's existing soldiery has been unable, whether because of a lack of skill or numbers, to shift the tide of the war in its favor.

Finally, some states consider themselves to be existentially threatened. Whereas a state that perceives a high external threat fears a military loss—even a severe one—there is no doubt that the polity itself will endure. But for a state that senses an existential threat, war is a matter of survival. The near-term prospect of annexation, conquest, invasion, or some combination thereof raises doubts about whether the country will continue to exist as an independent entity or whether critical terrain—for national defense, the functioning of the national economy, or both—will be cleaved away by a rival.

As the severity of external territorial threats increases and exceeds a state's ability to answer its demand for combat power using its existing soldiery, the government will pursue strategies to close the gap between the troops it has and the troops it needs. All else being equal, the more severe the external territorial threat is, the more likely it is that the state will recruit legionnaires.30 This dynamic can be compounded if legionnaires are poor fighters or are used in casualty-intensive operations. In these cases, a perverse feedback loop can emerge, as new legionnaire recruits become new personnel losses alarming the state's leaders. However, whereas some legionnaires can be poor fighters or be used as cannon-fodder, others—for example, the United Arab Emirates’ U.S.- and Australian-staffed presidential guard—are elite soldiers who match or exceed the capabilities of their citizen peers.

Can these demand dynamics exist in internal conflicts? Would states ever begin or expand legionnaire recruitment in the absence of an external foe? The article thus far has discussed government fears of internal regime threats, external regime threats, sectarian divides, and labor trade-offs as constraints on a state's appetite to enlist citizens. In some circumstances, however, these threats also can amplify a state's need for combat troops. For example, if a separatist insurgency attacked a capital, the government would conceivably respond by deploying troops or even expanding the military should a wider conflict begin. In cases where any of the four factors that my argument treats as supply constraints leads to a domestic military conflict—thereby creating a demand for combat power—recruitment will occur in a way similar to when external territorial threats spark a state's need for combat troops That is, as military losses mean a government's need for troops exceeds its existing supply of soldiers, and legionnaire recruitment becomes more likely.

For governments that recruit legionnaires to fight internal conflicts, questions about endogeneity inevitably arise; however, it bears emphasizing that the supply-side factors that can curtail a government's domestic recruitment do not always result in a demand for more troops. My theory's supply-side variable affects a state's recruitment policies via the political risk that a government anticipates will result from citizen enlistment when internal regime threats, external regime threats, sectarian cleavages, or labor trade-offs are present. Put differently, the imagined or anticipated consequences of citizen recruitment constrain the government's flexibility and desire to enlist soldiers from the state's own population. Only if, for example, a feared coup risk becomes an actual coup attempt could the state's demand for added combat troops be created, as previously described.


States can find themselves caught between competing imperatives: a territorial threat that requires them to raise more troops and a domestic context that makes mobilizing sufficient numbers of citizen soldiers politically fraught. Yet, states cannot hold one source of danger constant, setting domestic concerns aside to focus exclusively on external threats, or vice versa. They must find policies that satisfy both imperatives simultaneously; recruiting legionnaires allows states to fill the gap between the soldiers they need and the citizen-troops they believe can safely mobilize.

Conceptually, legionnaire recruitment enables omnibalancing.31 In selecting among options for recruiting more soldiers, states choose policies that allow them to balance simultaneously among competing internal and external dangers. In my theory, governments continue to recruit citizens as long as doing so does not create acute political risks. When the domestic factors that I have described convince governments that expanded citizen recruitment poses untenable dangers, they are more likely to recruit legionnaires, viewing them as politically cost-effective substitutes. On the demand side, escalating levels of external territorial threat create imperatives to expand the soldiery. When states experience major personnel and territorial losses—and particularly when they perceive a threat to their survival—they make a pragmatic decision to use legionnaires to address their combat needs.

How do legionnaires sidestep the political risks that labor trade-offs, sectarian cleavages, and external or internal regime threats create for citizen recruitment? For governments facing labor trade-offs, legionnaires help keep citizens on the production line without leaving the military short on personnel or supplies. For leaders fearful of exacerbating sectarian cleavages, recruiting legionnaires avoids the risk of enlisting members from suspect citizen communities who may have grievances with the government. Leaders fearful of threats external to the regime but internal to the state, as with an insurgency, derive these same benefits with legionnaires. For leaders fearful of threats from within the regime, legionnaires help them avoid recruiting citizens who could be loyal to political rivals.

On the demand side, legionnaires assist states in fulfilling their growing need for combat personnel. They offer a flexible option for governments seeking to respond to battlefield dynamics without upsetting a delicate political balance at home. When states are fighting for survival, their demand for manpower grows to the point of becoming inelastic—they become willing to pay any political price for more combat power. In practical terms, states will try to maximize the quantity of soldiers they can field to the country's defense. An existential threat thus spurs states to surge all available manpower sources into the war effort. Although the government may still face fears of internal regime threat, external regime threat, or other domestic factors that previously limited citizen-enlistment, these issues cease to constrain citizen or legionnaire recruitment—assuring that the state's survival overrides all other concerns.

As outlined in table 1, growing levels of external threats, domestic constraints, or both, increase the likelihood that states will implement new measures to recruit legionnaires or to expand existing foreign recruitment policies. When states perceive a low external threat and no political constraints on recruiting at home, new or expanded legionnaire recruitment is unlikely. Without a need to expand the soldiery, and absent the domestic circumstances that could make citizen recruitment especially risky, states will mobilize individuals they have readiest access to—citizens.

When states face low threats abroad but moderate constraints at home, or high territorial threats but low barriers to recruiting domestically, legionnaire recruitment is somewhat likely. It is by no means certain, however, and this recruitment choice is far less likely relative to other combinations of higher variable values. Whether governments ultimately decide to recruit legionnaires can depend on subtle factors within the state's specific context. A state facing high threats but low constraints may recruit legionnaires if it judges that rates of attrition are outpacing its ready ability to put sufficient numbers of citizens into uniform. In such contexts, states may view legionnaires more as a practical option than as a political hedge—that is, as personnel who can be swiftly surged to the front. Conversely, these same states could eschew legionnaire recruitment entirely, particularly if they have massive citizenries that have not been mobilized or efficient enlistment mechanisms.

States that encounter low threats abroad but moderate constraints at home are similarly somewhat likely to recruit legionnaires. Such governments could believe that they enjoy a stable peace or that their wars are going well, but nonetheless fear that the domestic issue constraining citizen recruitment is so politically threatening that they enlist legionnaires to avoid upsetting the balance at home. A decision to recruit legionnaires could be especially appealing if the same state's ongoing combat operations, though successful, unexpectedly expand in scope, as with the opening of a new front in the war.

Still, other variable combinations increase the probability of legionnaire recruitment. When states face low threats abroad but high constraints at home, legionnaire recruitment becomes very likely. In this combination of variable values, the stakes of expanded citizen enlistment are so perilous that governments turn to legionnaires to avoid disrupting the delicate political balance they must maintain at home. In this context, recruiting legionnaires also can serve as a hedge for a future spike in demand; enlisting foreigners expands the number of combat personnel available for mobilization should violence flare at home or abroad.

Greater levels of external threats may increase the likelihood of new or expanded legionnaire recruitment. States that face high external threats, even if they are dealing with only moderate domestic constraints, are likely to begin or expand the enlistment of legionnaires in response to combat troop and territorial losses. Doing so enables them to avoid implementing expansive citizen enlistment measures that could create political risk. In cases where a government confronts both high threats abroad and high constraints in its ability to recruit domestically, legionnaire recruitment becomes very likely. The degree and immediacy of the need for troops, coupled with the severe obstacles that bedevil citizen enlistment, make legionnaires an especially attractive option. In the rare case of a state perceiving a threat to its very existence, the recruitment of legionnaires is highly likely. The imperative to ensure the country's survival likewise overrides any constraints on recruiting domestically that may have previously curtailed mobilization efforts.

I evaluate three types of evidence to gauge support for my argument. First, I review trends from a large-N dataset on legionnaire recruitment, outlining initial findings consistent with elements of my theory and inconsistent with alternatives. Second, given the importance of perceptions in my argument, a large-N analysis alone is insufficient to evaluate the causal processes I posit. I therefore use congruence tests to sketch recruitment policies across World War II combatants—a small-N approach that suggests further support for my argument and illustrates its applicability across a single conflict. Third, I test my theory employing before-after design and process tracing across a wartime case—Nazi Germany.32 Using a single detailed case study has a key drawback: it allows me to illustrate how only one of the four domestic factors that I argue can limit citizen recruiting (in Germany's case, labor trade-offs) spurs legionnaire enlistment. Nonetheless, it permits a thorough test of the causal processes that underpin my theory and alternatives. And although Germany represents a single case, it contains multiple recruitment policy observations, enabling within-case tests of my argument.33 The German case therefore allows me to examine the strength of my argument across all levels of external threat amid a backdrop of sharp labor trade-offs that curtailed the government's leeway to recruit citizens.

To evaluate my theory and the alternative arguments described earlier, I compiled a country-year dataset of states’ legionnaire recruitment policies over the past two centuries. The data show that legionnaire recruitment is far from rare. From 1815 to 2020, ninety-one states implemented 231 such policies (see figure 1 and the online appendix).34

States That Have Recruited Legionnaires.

Figure 1.
States That Have Recruited Legionnaires.
Figure 1.
States That Have Recruited Legionnaires.
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I gathered the data from a review of legislation, military commendations, and order-of-battle assessments, as well as from unclassified and declassified documents from the U.S. Department of State Office of the Historian, the National Security Archive, and the Central Intelligence Agency FOIA Reading Room. Additionally, beyond adhering to my definition, included legionnaire recruitment policies had to meet five criteria. First, I limited my review to policies initiated from 1815 to 2020 and enacted by governments in the Correlates of War State Membership dataset.35 Second, recruitment had to be overt. Third, the policies had to endure either a minimum of six months or the length of a conflict, if initiated in wartime.36

Fourth, policies had to yield at least 100 new personnel—a cutoff that I selected for several reasons.37 First, many militaries are small. For states with such forces, even 100 new recruits can be a significant addition to the ranks, or they can represent the majority or entirety of an officer corps, or, in some cases, both—a practice that was particularly common in postcolonial Africa and in Eurasia after the Cold War. Additionally, this threshold approximates that of a company-sized formation—an organizational building block for military operations in the modern age for armies of all sizes. The threshold thus allows the data to account for cases in which states recruit legionnaires to staff praetorian guards or special forces units. It is likewise high enough to exclude cases in which one or a handful of foreigners were recruited in error or in which states recruited a single foreign officer for a senior or symbolic role.

Fifth, I ensured that all recorded policies represented the most puzzling cases—where states recruit foreigners with whom they have no ties. Therefore, I excluded foreign recruitment where a state's conceptualization of citizenship was explicitly transnational or where governments recruited only foreign coethnics of a regime ruled by an ethnic minority.38 My rationale for excluding these instances is that the state may not view these recruits as being devoid of preexisting ties or a shared identity—that is, not as truly a matter of “foreign” recruitment.

The data suggest initial support for the demand side of my argument. Governments recurrently began recruiting legionnaires during conflicts; roughly 80 percent of the 231 policies occurred in the midst of hostilities. Moreover, the data show that, for many states, legionnaires have always been a core component of how they build their military power. France, post-independence India, and the United Kingdom, for example, have never not recruited legionnaires. Their militaries are inherently hybridized. For others—such as Iran, Japan, Russia, and the United States—legionnaires have been a linchpin of every major interstate conflict they have fought. In still others—including Angola, Thailand, and Uganda—legionnaires were a core component of the forces that governments relied on to battle insurgents and political enemies. For these governments, legionnaires are intimately entwined with domestic politics.

The data suggest less support for alternative explanations. Rather than a product of imperial legacy or ties to former colonies, just one third of the 231 recorded policies that I examine were implemented in states that were colonial empires. More than half of legionnaire recruitment polices were implemented in countries that were never colonial powers. Additionally, acquiring specific skills or expertise does not appear to be a widespread motivator of recruitment; slightly more than one quarter of the 231 recorded policies were clearly motivated by this goal. Arguments attributing foreign recruitment to small population size are likewise unconvincing.39 Although small Arab monarchies recruit foreigners, states with large populations—such as China, India, and the United States—often do so as well.

The data also showcase trends that challenge narratives about the evolution of modern militaries. Legionnaire recruitment has remained a consistent practice in the past two centuries (figure 2). Moreover, the number of policies in use at a given time has continued to grow (figure 3). These trends are especially striking given the increase in the number of states in the international system since decolonization and the resurgence of private military contractors since the end of the Cold War.

Proportion of Legionnaire-Recruiting States Globally

Figure 2.
Proportion of Legionnaire-Recruiting States Globally
Figure 2.
Proportion of Legionnaire-Recruiting States Globally
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Legionnaire Policies in Use Globally

Figure 3.
Legionnaire Policies in Use Globally
Figure 3.
Legionnaire Policies in Use Globally
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Implementing legionnaire recruitment policies often has enabled states to recruit significant numbers of troops, providing them a sizable boost in combat capacity. For instance, the United States mobilized more than one quarter million foreigners during World War I.40 Years later, having triumphed in the Chinese Civil War, Communist authorities enlisted entire brigades-worth of Japanese veterans and prisoners of war (POWs), using them to help hunt remaining Nationalist forces and later during the war in Korea. In smaller armies, legionnaires can represent a large plurality or even a majority of a military. In the 1970s, not only did Idi Amin double the size of Uganda's forces, but he flooded the ranks with foreigners—such that by 1978, only a quarter of the military was Ugandan.41 In the 1980s, nearly two-thirds of the Emirati army comprised legionnaires, who played a particularly powerful role in staffing the praetorian guard, while in the same period, foreigners represented nearly 80 percent of Kuwait's military.42

Even when not serving in massive numbers or constituting a majority of personnel, legionnaires often become the preferred combat force of the governments they serve, playing a disproportionate battlefield role despite representing only a modest proportion of a state's overall manpower. Although France's Foreign Legion has represented only a small fraction of total French troops, it was a centerpiece of the country's military campaigns in the nineteenth and twentieth centuries, playing particularly prominent roles in Indochina and Algeria. In the past decade, the unit has remained a linchpin of French counterterrorism operations in West Africa, including the 2013 intervention in Mali.43 Similarly, during the 1970s, the roughly 4,000-strong legionnaire force of exiled Chinese Nationalists was a central feature of Thailand's counterinsurgency campaign against communists in the north.44 Far from an aberration, refugees and exiles from Europe and the Soviet Union provided the backbone of what became the U.S. special forces community after World War II.45 More recently, Iran relied heavily on its legionnaire-staffed Fatemiyoun and Zaynabiyun Divisions for combat in Syria, despite having amassed a military boasting more than 500,000 citizen troops.46

Overall, the data suggest a strong link between states’ efforts to enlist legionnaires and conflict—the demand side of my argument—while suggesting less support for alternatives. Tracking legionnaire recruitment comprehensively demonstrates that these troops are an enduring and consequential tool of security policy and have been mobilized by a diverse community of states.

Building on insights from the large-N analysis, I next use congruence tests to show how the internal and external variables that my theory identifies help explain why major World War II combatants recruited legionnaires.47 France, the United Kingdom, and the Soviet Union enlisted foreigners in the face of invasion, seeking every possible soldier in battles for national survival. Other states, including Italy and Japan, enlisted them amid a confluence of labor shortages and acute combat needs, redoubling their efforts as invasion loomed. Likewise, the United States moved to recruit legionnaires in preparation for joining the war, expanding this policy after it entered the conflict. Across diverse combatants, legionnaires waged offensives, held contested territory, and defended the states that recruited them against invasion.

Conflicts such as World War II feature tremendous citizen recruitment. Yet, the gap between the total number of citizens that combatants could have mobilized and the number they did mobilize might be more than one would expect. Even at the height of the war, Germans in uniform never eclipsed 10 percent of Germany's citizenry—a proportion on par with other combatants.48 So, why did major participants recruit legionnaires?

The German offensives that began in 1940 shattered the optimism that France had voiced when declaring war in September 1939. As France's prime minister despaired within days of Germany's springtime advances, “We have been defeated. … The front is broken near Sedan; they [Germans] are pouring through.”49 Despite boasting nearly 1 million soldiers and another 4 million in reserve, France in the face of conquest sought to recruit émigrés, recently interned aliens, and exiled Polish servicemen into uniform.50 Sadly for France, the speed of German advances meant that only two such regiments were in the field, and two more being raised, when Paris fell.51

Throughout the Battle of Britain and the Blitz, the British government recruited a diverse foreign cadre into the Royal Air Force.52 Britain swiftly replicated legionnaire recruitment elsewhere in its military. By July 1940, it was enlisting Czechs, Spaniards, and other Europeans across all combat branches, as well as Polish pilots who had escaped France.53 By November, Britain had expanded its recruitment to permit aliens of neutral nations to serve.54 Given the stakes, Prime Minister Winston Churchill saw even the riskiest foreigners as worth mobilizing, affirming: “I see no question why enemy aliens, wishing to fight against Germany, should not be incorporated in a military body … where they can be under constant observation.”55 True enough, Britain enlisted some 10,000 Germans and Austrians, using them as airmen, infantrymen, and special forces commandos.56

Similar conditions led to the recruitment of legionnaires in the East. The Soviet Union was ill-prepared when Germany invaded in June 1941, and in mere months, the Red Army had been pushed back to the gates of Moscow itself. Desperate, Soviet authorities sought to mobilize anyone able to fight to avoid the fate of France and the Low Countries. Orders given to the Soviet 16th Army at the Battle of Moscow show how authorities perceived the stakes:

“There is nowhere left to fall back, and no one will allow you to do so. By using any and the most extreme methods, you must immediately bring about a turning point.”57 Between its existing soldiery and massive population, the Soviet Union had no shortage of citizens it could have mobilized, and indeed, prior to Germany's invasion, it had no need for foreign recruits. But with the country's existence threatened, the Soviet government, on August 12, 1941, gave amnesty to Polish POWs and deportees, raising three Polish-staffed divisions and subsequently amassing hundreds of thousands of legionnaires by the war's close.58

The United States also moved to recruit legionnaires, even before it officially entered the war.59 When the government instituted the country's first peacetime draft in September 1940, the measure applied to citizens and aliens alike, including foreigners in the country only temporarily.60 Weeks later, it also took steps to attract foreign volunteers. The Nationality Act of 1940 both waived the requirement that aliens declare an intent to acquire citizenship as a condition for enlisting and provided recruits an option to naturalize after three years of honorable service. With the country facing labor shortages after 1943, Congress passed legislation in 1944 that offered immediate citizenship to foreigners, even if they were abroad at the time of enlisting in the U.S. military.61

The variables that my theory identifies likewise help explain legionnaire recruitment by Axis governments. Within months of joining the war in 1940, Italian forces in North Africa and Greece were facing stiff resistance and mounting casualties that intensified the military's need for additional soldiers. Although Italy had experienced a labor surplus even into the late 1930s, recruiting from its citizenry proved challenging; since 1938, Italy had supplied tens of thousands of workers annually for German industries. With so much labor having been exported, by the winter of 1940, Italy perceived sharp trade-offs in how its citizenry was best being used. In December, it attempted to address the imbalance by barring Germany's recruitment of Italian workers subject to compulsory service; still, Italy failed to gather sufficient numbers of enlistees.62 With heavy fighting in the Balkans just as Italian forces joined Operation Barbarossa, Italy authorized the recruitment of a Croatian brigade in July 1941 to supplement its contingents in the East.63 In November, the Italian government approved measures to begin enlisting Arabs and POWs from the British Indian Army to bolster its forces in North Africa.64 By 1942, Italy had implemented additional policies and was recruiting tens of thousands of Serbo-Croatian, Slovenian, and Muslim volunteers to supplement its forces in Yugoslavia.65 Amid mounting casualties in Russia and no flexibility on the labor front, Italy also began recruiting Cossacks for light cavalry and as scouts; even as invasion loomed, it continued to rebuild decimated legionnaire units for the country's defense.

Similarly, labor trade-offs and rising combat demands spurred Japan's legionnaire recruitment. Between operations in China since 1937 and its attack on Pearl Harbor in December 1941, Japan had used a combination of measures—including labor controls, the mobilization of women, and the import of foreign workers—to ensure it could draw both soldiers and laborers from its citizenry and subjects in Korea and Taiwan. But by early 1942, Japanese authorities had acknowledged that existing measures no longer satisfied its manpower needs.66 Compounding matters, following the United States’ entry into the war and Japanese conquests in British Malaya, Singapore, and the Dutch East Indies in early 1942, Japan faced the task of holding and defending vast territory while sustaining critical production. Amid this confluence, in March 1942, Japan ordered its command in Indonesia to recruit “local troops or police … to clean up the remaining enemy forces.”67 In Indonesia alone, Japan was subsequently able to enlist roughly 180,000 recruits.68 By the summer, the Japanese government had implemented similar policies in Burma, Malaysia, Mongolia, and the Philippines. Explaining the logic of these recruitment policies, Japan's army ministry in January 1942 had stressed that, given labor constraints at home and “in consideration of difficulties in sustaining the level of forces, and the sacrifices we have to make, it is not the time for debate but for urgent measures to utilize [local] people … to build troop strength.”69 In 1944, with fears of invasion increasing, Japan began conscripting legionnaires to defend the empire.

In sum, several World War II combatants began or expanded their recruitment of legionnaires to supplement their citizen forces, drawing substantial numbers into battle and prolonging their war efforts. The manner in which these policies unfolded suggests further support for my argument; to test it more fully, I offer an in-depth examination of Germany's policies.

The German military's transition during World War II from an exclusively citizen force to one inundated with legionnaires can be explained by my theory. Here, I describe the baseline from which Germany's wartime recruitment policies departed: a prewar military manned by citizens and with Hitler opposed to legionnaire recruitment. I then evaluate three phases in German recruitment policies from 1940 to 1945, with each period outlining the domestic context, describing the external threats, and showing how these variables sparked legionnaire recruitment—both in the creation of entirely new policies and by the expansion of existing measures to harness untapped foreign manpower.70

By the spring of 1940, Germany was confronting new trade-offs in using its citizen labor force—one of the factors that my theory asserts may limit a government's appetite for recruiting citizens into military service. For this reason, Germany subsequently faced moderate constraints in recruiting domestically—a challenge that endured for the next five years. I also show how Germany progressed through three phases of the external dangers it perceived: low (April 1940 to October 1941), high (November 1941 to November 1943), and existential (December 1943 to April 1945). Amid these supply-and-demand pressures, legionnaire recruitment transformed the German military from an exclusively citizen force, to one that enlisted a small cadre of Western European legionnaires, to a military increasingly staffed with Eastern Europeans, and finally to a war machine that threw every foreigner it could into combat. I conclude this section with an evaluation of alternative arguments, showing the greater explanatory power of my theory.


World War II Germany presents a difficult test for my argument. Given a racial ideology that cast foreigners as inherently dangerous, Germany's prioritization of autarky in war resources, and Hitler's explicit prewar opposition to legionnaires, the scholarly consensus on citizen recruitment should be easy to corroborate. For these reasons, the case presents a hard test for my theory. Still, one could instead argue that the greater value that Nazi ideology attached to German lives over foreign ones makes the case one in which legionnaire recruitment could be expected to occur. Foreign recruitment therefore would be part of a strategy to shield citizen-soldiers from casualty. If this interpretation were correct, Nazi Germany would be more appropriately classified as an easy testing ground for my argument, rather than a difficult one, as I assert. Given the importance of this issue, I explicitly examine the case for evidence that this alternative perspective is correct. In marshaling evidence, I draw on Hitler's conversations, German High Command (OKW) records, documents from the German Federal Archive (Bundesarchiv) and the U.S. National Archive, and a robust secondary-source literature.

The case study's scope bears elaboration. The Wehrmacht is the most widely known German actor in the war, with the Schutzstaffel (SS) often associated with Hitler's personal guard, racial policy, and concentration camps. However, its armed component—the Waffen-SS—became a major force in the German military machine, buttressed by a reputation for brutality and operations in the bloodiest theaters of the war. I therefore examine German recruitment into both the Wehrmacht and the Waffen-SS—a choice that makes sense for four reasons. First, in 1939, Hitler placed the Waffen-SS under the OKW's operational control, together with Wehrmacht components; administratively, the Waffen-SS existed on the battlefield as did other combat branches.71 Second, troops in the Waffen-SS carried the same combatant status as Wehrmacht servicemen, and Waffen-SS service counted as national military service.72 In the eyes of German authorities, members of both the Wehrmacht and the Waffen-SS were soldiers.

Third, Hitler intended the Waffen-SS to act as a ground combat branch, viewing it as essential in cementing a reputation that he planned to leverage after the war: “People must know that troops like the [Waffen] SS have to pay the butcher's bill more heavily than anyone else. … The SS knows that its job is to set an example … and that all eyes are upon it.”73 In legal terms, and accounting for Hitler's intentions, the Waffen-SS was a combat branch of the German war machine, just like the Wehrmacht. Fourth, for Hitler, racial purity was the bedrock of Waffen-SS effectiveness and loyalty.74 As an exemplar of Aryan military prowess and Nazi racial ideology, the Waffen-SS, even more so than the Wehrmacht, was an organization from which legionnaires were particularly unlikely to emerge.


Until early 1940, Germany's military epitomized the citizen-army. Reinstating the draft in 1935, Hitler built an expansive force comprising the Reichsdeutche—ethnic German citizens of Germany. Moreover, the invasion of the Rhineland, the annexation of Austria, and the annexation of the Sudetenland expanded the prewar citizenry from which Germany could recruit troops. From 1934 to 1939, Germany's soldiery ballooned from some 315,000 citizen-troops to more than 2.7 million men.75

Two other points are central in understanding how surprising and fundamental the shift to recruiting legionnaires would be. The first is Germany's emphasis on autarky. Beginning 1936, Hitler stressed self-sufficiency as the prerequisite for Germany's success and expansionist campaign: “I consider it necessary that now, with iron determination, a 100 per cent self-sufficiency should be attained in all those spheres where it is feasible, and that … national requirements in these most important raw materials be made independent of other countries.”76 For a regime in which autarky was a watchword, the prospect that a plurality of the most critical resource of all—soldiers—would come from beyond the Reich would have been unimaginable.

Given his ability to shape policies to his preference, a second critical point concerns Hitler's views of legionnaires. Hitler had observed prolific legionnaire recruitment during World War I—and was left deeply hostile to these policies. He viewed foreign recruits as harmful to military cohesion and as political and security dangers to the governments that enlisted them, once asserting of legionnaires in the Great War: “The fall of the Habsburg monarchy clearly shows the full size of this danger. On that occasion, too, it was thought the other [foreign] peoples could be won over … by giving them a military formation in the Austrian Army. Yet at the decisive moment it became obvious that precisely these men were the standard-bearers of rebellion.”77 Legionnaires would find no home in the German military; to Hitler, the logic was clear: “If we wish to preserve the military power of the German people, we must be careful not to give arms to the peoples of the countries we have conquered or occupied.”78 Nonetheless, the variables that my theory identifies eventually led the government to abandon this absolute prohibition. By 1945, legionnaires staffed every service branch, from the standard-bearers of Nazi ideology in the Waffen-SS to the air, ground, and naval branches of the Wehrmacht.


In the spring of 1940, Germany launched a series of offensives that led to a rapid spate of territorial gains. These early wartime successes in Western Europe, however, belied a government that would increasingly be hard-pressed to secure sufficient citizen troops. From April 1940 to October 1941, German authorities judged that the country confronted a tangible constraint on the government's ability to recruit from the citizenry, as the needs for war production escalated and imposed sharp trade-offs in the use of German labor. Specifically, would German workers best serve the war effort in the factory or on the front lines? Given this labor trade-off, I code Germany as facing a moderate constraint on its ability to recruit domestically. Despite the perceived low external threat, the combination of Germany's domestic context and the military's offensive operations and growing territorial control spurred the government to recruit a select cadre of legionnaires.

Moderate-level Domestic Constraints. Although Hitler had been unfettered in reinstituting conscription in 1935, by early 1940, Germany was facing new manpower challenges, in the form of trade-offs in its ability to meet the combined needs of war production and combat service. As such, Germany escalated from a low-constraint environment to a moderate-constraint one. How did this constraint on recruiting domestically emerge?

The measures that Hitler's government had imposed to stem unemployment in the 1930s, coupled with qualitative changes in German labor during these years, created new limits on his leeway to recruit from the citizenry, arising at a most inopportune juncture. The application of the draft from May 1939 to May 1940 had deprived Germany's labor market of nearly 4 million workers, with trends continuing apace thereafter.79 Simultaneously, as its troops marched west in 1940, Germany officially reached full employment. Now, unlike prior to 1940, Germany no longer had an excess citizen labor supply from which to recruit. Additionally, qualitative changes in the workforce erased the government's room for maneuver. In 1934, citizens had been locked into their jobs and, by the end of the decade, the government's policies had unintentionally pushed many German workers into unskilled or semi-skilled jobs.80 As a result, labor mobility had largely evaporated by 1940. As prewar policies eroded German labor's flexibility, by 1940, the government's latitude to sustain war production while leaving sufficient recruits for the military had been constrained.

With the launch of its Western campaign in 1940, Germany faced trade-offs between its demand for soldiers and its need for laborers. The War Economy and Armaments Office of the Armed Forces High Command (WiRüAmt) consistently raised this very issue to Germany's leadership. In the summer of 1940, WiRüAmt's chief, Gen. Georg Thomas, reported that Germany already faced 300,000 armaments vacancies and that, by November, fewer than a third had been filled.81 Over the next several months, the gap between German labor's ability to meet the government's demands for both recruits and matériel only widened, despite measures to cut down on consumer goods and non-immediate production.82 But in early 1941, Hitler learned that the armaments industry alone faced a shortage of 1.2 million laborers; the WiRüAmt judged that only 200,000 of these job vacancies could be filled.83

Operation Barbarossa, initiated in June 1941, sharpened these trade-offs as the war expanded. As the WiRüAmt reported, “The more the demands of the armed forces are in regard to personnel, the fewer will be the number … to go into the armaments industry or to the overall economy.”84 Germany's labor difficulties only grew in the following weeks, with General Thomas reaffirming in October that “in the area of manpower supply, the point has been reached today whereby … there is no longer an ‘as well as’ but rather an ‘either or.’ Either the manpower needs of the troops or the manpower needs of armaments are to be covered.”85

Low-level External Threat. In this period, Germany perceived a low threat coming from abroad. German officials’ triumphant language privately and publicly, the military's low casualty levels, Hitler's comfort with troop loss rates, and the government's expectations of victory explain why it receives this coding. On April 9, 1940, German forces invaded Denmark and Norway, setting off a series of rapid victories and leading Hitler to crow that Germany's recent operations would be remembered “as the most daring piece of impudence in history.”86 Trends thereafter fed German optimism, with Belgium, France, Luxembourg, and the Netherlands all falling by June. In this period, Hitler had become so confident of victory on the Continent that he briefly authorized reductions in the infantry in favor of boosting naval and air personnel for an invasion of Britain.

The Nazi war effort received other boons. With the signing of the Tripartite Pact in the fall of 1940, Germany could count Italy, Hungary, Japan, and Romania among the Axis powers, and thus on mobilizing hundreds of thousands of additional troops.87 Low casualty rates kept German authorities emboldened; of roughly 6 million Waffen-SS and Wehrmacht soldiers, in 1939 and 1940, German combat losses had totaled just 102,000 fatalities.88 In June 1941, the war took a transformative turn when the German government dispatched 3.3 million soldiers to invade the Soviet Union—buttressed by nearly 690,000 allied troops.89 Although the invasion would eventually be the undoing of Germany's war effort, between the summer and early autumn, the government's optimism was undimmed. Boasting to his inner circle on July 31, Hitler proclaimed, “To all intents and purposes the war is won.”90

Limited Recruitment of Legionnaires. Despite Germany's perception of a low external threat, the labor trade-offs that the government faced by spring 1940, coupled with Germany's expanded territorial control in Western Europe and its offensive operations in the East, led to new measures that brought the first legionnaires into Nazi ranks. Both the limited numbers of legionnaires Germany recruited and the limited demographics it recruited from represent important baselines from which its recruitment policies later departed.

Amid labor shortages, Hitler, on April 20, 1940, authorized the Waffen-SS to recruit in Denmark and Norway for a new regiment, followed by Belgium and the Netherlands.91 Although the Waffen-SS was the first to enlist legionnaires, it was not alone for long. With the war's eastward shift creating new manpower demands, Hitler, on June 29, 1941, ordered both the Waffen-SS and the Wehrmacht to raise new legions. The former accepted volunteers from Denmark, Flemish Belgium, the Netherlands, Norway, and Sweden, while the latter recruited Croatian, French, Spanish, and Walloon Belgian volunteers—groups that Nazi ideology cast as racially acceptable nationalities.

At this point, Germany's recruitment of legionnaires was extremely limited. Given Hitler's optimistic view of Germany's external environment, large numbers of legionnaires were unnecessary—and, given his personal hostility toward them, not desired. The government, therefore, adhered to clear limitations in deciding how many legionnaires to mobilize and which nationalities to accept for service, rejecting thousands of foreign volunteers. When the legionnaire-staffed SS-Wiking was established in 1940, enlistment standards were identical for its Nordic applicants and its German volunteers; and even through 1941, the Waffen-SS rejected most foreigners who applied.92 Likewise, although the Wehrmacht eventually mobilized French recruits, far fewer were accepted for service than were available. Fearful of the risk that recruiting and arming 30,000 Frenchmen could create, Hitler instead stipulated in July 1941 that no more than half be accepted.93

Germany also categorically excluded certain foreign groups for recruitment, including significant numbers of noncitizen coethnics. For instance, on June 21, 1940, the 12th Infantry Division received orders that POWs “who are [ethnic] Germans … are to be shot after their identity is established.”94 Despite their ethnicity, these would-be recruits had betrayed their race in fighting for the Red Army and thus deserved no quarter. Similarly, internal debates show that, by April 1941, Gottlob Berger—a senior Nazi official responsible for leading Waffen-SS recruitment—proposed enlisting Ukrainians, only for superiors to unequivocally reject the proposal. He was told, “Legions shall never be permitted to be established in the Baltic states or in the Ukraine.”95 But in subsequent years, as Germany's labor constraints persisted and its perceptions of its external threats escalated, the country was forced to change many of its recruitment policies.


In November 1941 and subsequent months, Germany's recruitment of legionnaires exploded, as authorities acknowledged that the country would continue to experience the labor trade-offs that had already curtailed citizen enlistment. Simultaneously, mounting casualties and territorial setbacks in the East convinced leaders by winter 1941 that Germany was confronting a highly threatening environment externally. To meet this increased need for soldiers while maintaining production at home, Germany significantly loosened limitations it had imposed on legionnaire recruitment, both by enlisting members of ethnic and national groups that it had previously rejected for service and by taking its first, limited steps to conscript foreigners for soldiers.

Persistent Domestic Constraints. Government concerns in 1940 about trade-offs from drawing too heavily on German labor for soldiers continued to limit Hitler's appetite to recruit from the citizenry. Given the persistence of this trend, and that the government did not identify additional limitations in recruiting, I code Germany as continuing to experience moderate constraints in drawing on its citizens for troops. As Hitler lamented on December 29, 1941, of Germany's prospects and the stark connection between production output and combat needs, “The main problem today is the problem of labor.”96

In subsequent months, this labor shortfall continued to create trade-offs in how Germany perceived its combat needs and production imperatives. As a December 1941 WiRüAmt report described, “Since manpower reserves [in the economy] are no longer available, the inductions [into the military] are having a greater impact … on the scope of the armaments industry.”97 In March 1942, Hitler lamented similarly that the challenge of increasing “weapons production … is again a matter of labor,” while nonetheless mandating that losses in the East meant that “production in all areas must now … be tripled.”98

In an attempt to address these challenges, Germany increasingly used foreign workers—both volunteers and forced labor—to try to meet its rising combat and matériel needs.99 Nonetheless, in January 1942, General Thomas warned superiors that the use of foreign labor would not suffice in meeting the increasing needs of war production.100 Still, Germany's framing of these difficulties in the language of external security is telling. As Martin Bormann, chief of the Nazi Party chancellery, explained in May 1943, “The Reich's security is the first priority. … Everything must be subordinated to the goal of winning this war. Thus, foreign workers employed in the Reich are to be treated in such a way … that their full manpower is preserved for the German war economy.“101

High External-Threat Level. Although labor trade-offs remained a constant challenge, by the winter of 1941, Germany's threat perception had grown dramatically, surging from low to high. The country receives this coding because of the changing views of its leaders toward growing German casualty rates and territorial losses, as well as dimming prospects for victory. Optimism no longer pervaded discussions among officials in Berlin; instead, even Hitler began voicing fears about Germany's prospects in the war.

In November 1941, with German forces firmly engaged in some of the bloodiest battles of the eastern invasion, losses became impossible to downplay or ignore. The casualties sustained in the initial advance—which government and military officials had privately and publicly deemphasized in the summer and early fall—began to shift Germany's perceptions, particularly as new losses mounted. When, in December, the Red Army launched a counteroffensive outside Moscow, ultimately claiming the lives of nearly 200,000 German soldiers, the country's changed perception of the war was further cemented, with Hitler later describing the losses from this period as “a staggering blow” to the war effort.102

Battlefield trends from November 1941 to November 1943 solidified German perceptions of a heightened external threat, as unprecedented casualties and the loss of conquered territories created a desperate scramble to field more soldiers into battle (see table 2). Many German units in the East experienced total attrition of their initial strength, only to be fully reformed and obliterated again—a cycle that repeated often.103 As Germany's death toll mounted, discussions among senior political and military figures grew panicked, mirroring the high-threat language that my theory describes. Speaking to Hitler on July 26, 1943, about German losses in the East, Field Marshal Günther von Kluge, who first led the 4th Army and later commanded Army Group Center, acknowledged, “It's nearly unbearable the way it is now.” Hitler remarked that the entire theater faced a “desperate” situation.104 In November, reflecting on how combat in the past two years had dimmed German prospects for victory, he conceded, “If the enemy breaks through our defenses on a broad front, the consequences can hardly be imagined.”105 In the two years since the eastern march began, 1.3 million Nazi soldiers had died.

Table 2.
German Manpower and Fatalities, 1941–45
Total Personnel 7,234,000 8,310,000 9,480,000 9,420,000 7,830,000 
Combat Deaths∗∗ 356,528 566,947 789,752 1,756,256 1,287,540 
Percentage Killed 4.9% 6.8% 8.3% 18.6% 16.4% 
East 302,495 506,815 700,653 1,232,946 — 
West 11,033 12,000 11,000 244,891 — 
Other Fronts 43,000 48,132 78,099 278,419 57,495 
Final Battles — — — — 1,230,045 
Total Personnel 7,234,000 8,310,000 9,480,000 9,420,000 7,830,000 
Combat Deaths∗∗ 356,528 566,947 789,752 1,756,256 1,287,540 
Percentage Killed 4.9% 6.8% 8.3% 18.6% 16.4% 
East 302,495 506,815 700,653 1,232,946 — 
West 11,033 12,000 11,000 244,891 — 
Other Fronts 43,000 48,132 78,099 278,419 57,495 
Final Battles — — — — 1,230,045 

Combined Waffen-SS and Wehrmacht personnel.


Excludes prisoner-of-war deaths.

sources: Rolf-Dieter Müller, Hitler's Wehrmacht, 1935–1945, trans. Janice W. Ancker (Lexington: University Press of Kentucky, 2016), pp. 44, 81, 186; and Rüdiger Overmans, Deutsche Militärische Verluste im Zweiten Weltkrieg [German miltiary losses in World War II] (Munich: Oldenbourg Verlag, 1999), p. 266.

Elevated Legionnaire Recruitment. The combination of moderate domestic constraints and an increasingly dire external environment led Germany to embrace unprecedented measures to mobilize foreign soldiers. Until the fall of 1941, most German troops had comprised Reichsdeutsche, with a small cadre of Western European legionnaires. But in November 1941 and subsequent months, the government massively expanded the number of legionnaires it recruited and mobilized. Most strikingly, before Operation Barbarossa, German authorities had explicitly forbidden the enlistment of Russians and other Soviet citizens. But as rising losses changed this view, the numbers and types of foreigners that Germany recruited reached once-unimaginable levels.

In November 1941, Hitler, recognizing that Germany faced an acute external threat, authorized German units to enlist Russians, sparking growing recruitment of legionnaires euphemistically dubbed “willing volunteers” (Hilfswillige). Yet, when the threat outlook had been lower, Hitler's distrust and disdain for Russians could scarcely have been clearer. In September, he had described them to attendees at a dinner soiree as “brutes,” “animals,” and worse—but above all, as individuals never to be recruited and armed.106 Yet, when German views of the war shifted and labor remained inflexible at home, Hilfswillige recruitment not only began, but swiftly ballooned, with growing numbers of Soviet legionnaires organized into the Wehrmacht's eastern battalions and POW camps scoured as recruiting grounds.107 Reeling from mounting casualties, by mid-1942, Germany had authorized its forces to conscript Russians and to fill 10 percent of units with these draftees. The effects on the composition of German units were tremendous; by August, every seventh soldier in the 18th Panzer Division was Russian.108 By June 1943, Russians alone swelled to more than 800,000 troops.109

German authorities acknowledged that the perception of high external threats fueled this recruitment trend. A classified March 1943 memorandum from Gen. Heinz Hellmich, then commanding Germany's eastern-staffed formations (Osttruppen), illuminates the policy's rationale.110 He describes how, in the face of mounting German losses, “the [Soviet] population's readiness to help had to be exploited as far as possible.”111 Given the state of the war, Hellmich affirmed that Russians and other Soviets must “not only give their strength in the form of work but must be ruthlessly exploited to the last and sacrifice their lives for us.”112 Germany did just that.

German authorities recruited widely across other Soviet populations. In December 1941, the government ordered the Wehrmacht to recruit Armenians, Georgians, and Muslims from the Caucasus for Ostlegionen—military formations comprising several battalions of recruits from Soviet minority groups—with Cossacks later also targeted for enlistment.113 The policy departure that these orders represent cannot be overstated. Months earlier, when Germany had perceived little threat abroad, Hitler had rejected recruiting from these groups, stating unequivocally in July 1941 that “not the Slav, not the Czech, not the Cossack nor the Ukrainian” would ever bear German arms.114 Even into early autumn, he rebuffed proposals to enlist Soviets, warning that “ruling races could only contribute to their downfall if they armed those whom they oppressed.”115 But given Germany's persistent labor constraints, the new perception of acute threats led the government to enlist those it had previously foresworn. As a result, by September 1943, nearly a million Soviets were wearing German uniforms.116

In 1942 and 1943, Germany also expanded the Waffen-SS's ability to recruit foreigners. Reversing prohibitions against recruiting in the Baltics, the commander of the SS, Heinrich Himmler, announced in 1942 that Hitler himself had “commanded the establishment of a Latvian and Lithuanian SS volunteer legion.”117 The change was enormous: if Hitler's disdain for Russians was infamous, he expressed even lower regard for the Latvians he now recruited. In July 1941, when Germany had seemed on the cusp of victory, Hitler sneered, “Stalin used the Latvians for … executions which [even] the Russians found disgusting.”118 In a similar shift, in March 1943, the German government reversed prohibitions on recruiting Ukrainians, creating the SS Division Galicia and attracting more than 32,000 volunteers in just the first two weeks, with numbers later reaching 100,000.119

The same combination of perceived high external threats and persistent domestic constraints likewise prompted the government to loosen its restrictions on recruiting legionnaires from Western Europe. In rosier days, Hitler had rejected thousands of French volunteers, asserting that, fundamentally, “France remains hostile to us. She contains […] a blood that will always be foreign to us. … There's no possibility of our making any pact with the French before we've definitely ensured our power.”120 But as losses grew and labor remained inflexible, he authorized the Waffen-SS to recruit personnel he had once prohibited.121 In less than a year, amid an escalating threat abroad and persistent constraints at home, Hitler's “no possibility” of relying more heavily on foreign recruits from occupied states had become an absolute certainty.


By the winter of 1943, German fears of an Allied invasion had reached a fever pitch; the survival of the Reich seemed uncertain. Consistent with my argument, German leaders’ perception that their country faced an existential threat overrode the feared labor trade-offs that had previously constrained the recruitment of foreign laborers and citizen workers; an insatiable demand for troops led the government to remove remaining barriers to mobilizing legionnaires. By the end of the war, this inelastic demand for manpower had pushed the government to all but abandon the professional force it had previously maintained; it instead embraced recruitment policies that surged every available manpower source into combat.

Ballooning External Threats. By December 1943, German military documents had begun carrying the stamp “invasion,” a key piece of evidence validating my coding that the German leadership perceived the war in existential terms.122 Combat losses fueled fears that the country's survival was at stake. Over Christmas 1943, Hitler lamented that losses in Ukraine and Crimea were so large that “we can't save anything. The results [for the war] are catastrophic.”123 Yet, so vital did the government perceive these regions that officials were willing to stomach massive casualties to keep them, with Hitler acknowledging the stakes: “We're obliged, if it's even possible, to defend this second Stalingrad—if it can be done somehow.”124 In subsequent battles in 1944, more than 18 percent of Germany's manpower—some 1.7 million men—died in combat; in 1945, more than 1.2 million of its soldiers perish.

The spring of 1944 brought catastrophe closer to Germany's borders, with the defeat of German forces in France claiming the lives of more than 500,000 soldiers, including Germany's most battle-tested units. Dread and disbelief increasingly marked conversations among German government and military officials. Reading a status update to Hitler in June, advisers were stunned: “Are the numbers correct? Of the 90th [Panzer Grenadier] there is almost nothing left. There is also almost nothing left of the 20th, which was just deployed. The 362nd … is pretty much gone.”125 Continued German losses that summer and fall only heightened the growing sense of desperation. Following the collapse of Army Group Center under the weight of a massive Soviet assault, the Red Army tore open a 300-kilometer-long gash along the length of the Eastern Front.126 With enemies seemingly poised to breach Germany's borders, on September 17, Hitler told advisers, “The best thing is to make clear to everyone that this battle is a struggle for life or death.”127 In private, he similarly confessed that war with the Allies had become no less than “a question of whether Germany will continue to exist at all or if it will be destroyed.”128

As German fears of invasion created an inelastic demand for troops, the labor trade-offs that had previously limited the enlistment of citizens and foreign workers no longer constrained recruitment. In the final months of the war, officials acknowledged—but were no longer swayed by—the damaging effects that mobilizing these personnel would have on production. Slapping down a proposal in March 1945 that laborers be diverted to repair railways, Hitler complained, “We can't afford that. It's sheer lunacy.”129 No longer seeking to mitigate labor trade-offs, Germany threw every available man—foreigner and citizen alike—into battle. Remarks from Himmler from July 29, 1944, capture the pragmatism of these policies; referring to the coming Allied onslaught, he warned, “there are no more miracles … we must earn everything ourselves.”130

All-out Legionnaire Recruitment. Fearing annihilation, Germany dismantled what limitations remained on the numbers and nationalities of legionnaires it enlisted. The first new policy arose as territorial losses after the winter of 1943 pushed hundreds of thousands of refugees, collaborators, and veterans of Axis militaries to flee toward Germany. By the spring of 1944, both the Wehrmacht and the Waffen-SS were drafting refugees from Soviet territories, and both induced and forced fleeing Western European collaborators into service.131 Even if one accounts for lost records, the scale of this recruitment was stunning. By April 1944, Soviet Hilfswillige and Friewillige comprised 12 percent of the entire German army in the field. Similarly, the Luftwaffe swelled to more than 300,000 Hilfswillige in the war's last eighteen months.132

Germany also mobilized legionnaires by recruiting from the armies of its fallen allies. After German forces occupied Hungary in March 1944, Himmler ordered the SS to accept all local volunteers, and by winter, German forces conscripted whole Hungarian units.133 Germany pursued similar policies in Bulgaria, Italy, and Romania, cannibalizing Axis armies and occupied territories in search of troops. Amending an order from November 1943, the OKW on June 26 extended Wehrmacht conscription to all foreign Germans and stateless persons with refugee or resettler identification, with the Waffen-SS following suit shortly thereafter.134

Germany also mobilized the remaining manpower pools that it had shunned earlier as politically and racially intolerable. In April 1942, Hitler had stated of Poles’ particular unreliability and danger, “Let's be cautious … history proves that the Poles have their nationality tattooed on their bodies.” Still suspicious, in 1943 he vetoed proposals to enlist them.135 Yet, in a complete reversal, in October 1944 the government authorized the acceptance of Polish volunteers into the military.136 Still, the most dramatic shift concerned liberation movements in occupied areas—a second potential pool of recruits that Germany had avoided. On June 8, 1943, Hitler had shut down all discussion of mobilizing these groups, affirming that, “above all, this must not happen.”137 But facing annihilation, Germany crossed this redline; in September 1944, Hitler authorized the anti-Stalinist Russian Liberation Army to field five divisions composed of Soviet POWs and slave laborers for Germany's war effort.138 The government also dropped its reservations regarding a similar Ukrainian movement, with Berger in late 1944 observing that, given the state of the war, recruiting from this group “could not do anything against Germany but … help considerably in solving the replacement [troop] problem.”139 Unlike the military Hitler had begun with, legionnaires became a vital component of Germany's war effort, persisting until the Third Reich's final days.


Nazi Germany's policies to recruit legionnaires provide strong support for my theory, but four alternative explanations also require evaluation. Although several fit components of the case, none fares well overall.

One alternative argument holds that states may recruit legionnaires to affirm or bolster international bonds with former colonies or with a diaspora.140 Germany did not recruit personnel from former colonies, so this variant does not fit the case. An examination of Germany's recruitment of noncitizen coethnics (Volksdeutsche) fares somewhat better. Volksdeutche recruitment did occur during the latter half of the war; however, the execution of this policy does not align with this alternative's expectations. Such recruitment, as Hanson and Lin-Greenberg describe, serves to “communicate ongoing trust and commitment,” but noncitizen coethnics were not consistently a priority of German recruitment efforts.141 The country did not begin to vigorously or expansively target Volksdeutsche for enlistment until the tide of the war began to turn against it, and its initial recruitment of this group occurred with clear limitations on how many enlistees Germany intended to mobilize. This disjuncture is curious given that Volksdeutsche, though noncitizens, would have possessed Germany's desired racial characteristics. Not until early 1942, however, did the Waffen-SS begin enlisting individuals from this population, and its initial efforts were far from robust, and tens of thousands were rejected for service; additionally, only in 1943 did Germany begin conscripting Volksdeutsche across occupied territories.142 There are also few indications that the recruitment of noncitizen coethnics was intended to foster favorable ties; as the war persisted, conscription was routinely imposed on resistant Volksdeutsche populations and over the objections of states where they were citizens. Moreover, from the perspective of Germany's leadership, these individuals seemed as disposable as Soviet and other enlistees. Even throughout early 1942, German units were given, and acted on, orders to execute enemy captives found to be Volksdeutsche.

A second alternative explanation holds that states recruit foreigners for their specific skills or to place experienced foreign officers into senior leadership roles.143 Germany's initial recruitment of Soviets in 1941 and 1942 conforms particularly well to the expectations of this argument; Nazi documents from this period highlight the utility of enlisting legionnaires who knew the local terrain and languages.144 Nonetheless, it fits poorly in explaining the bulk of German recruitment during the war. If recruiting personnel with particular area knowledge or language expertise had been a core German motivation, one would have expected legionnaires to have been deployed primarily in places where those skills would be an advantage. But by 1943, Soviet legionnaires were increasingly deployed far from their homes or outside the Soviet Union altogether—where their language skills or area knowledge would not have been useful. For example, Germany dispatched Azeri, Cossack, and Indian recruits to France, despite ongoing combat in the East.145 Alternatively, if recruiting senior officers with proven battlefield experience had been a German goal, it is unlikely that the government would have eschewed mobilizing captured enemy commanders until late in the war. Yet, Germany did so, for fear that these officers would cultivate too much autonomy or loyalty among Germany's legionnaires. Until 1944, Hitler rejected proposals to field Russian Lt. Gen. Andrei Vlasov and the Russian Liberation Army, despite Vlasov's evident skill against German forces during the Battle of Moscow.146 There is also little evidence to suggest that recruiting legionnaires with specific skills drove the recruitment of Western Europeans before 1941 or the conscription of Western and Eastern Europeans after 1943.

A third alternative explanation posits that the German government could have recruited foreigners to minimize citizen casualties.147 Evaluating this alternative is especially important in determining whether Germany classifies as a hard test for my theory. Details from the case, however, are inconsistent with viewing Germany's legionnaire recruitment as motivated primarily by a desire to preserve as many Reichsdeutsche soldiers as possible. First, Hitler saw German troops’ participation in combat—and the ensuing casualties that would inevitably result—as an opportunity to cultivate a reputation for ruthlessness and ferocity that he would leverage in ruling Europe after the war. As he asserted in January 1942 of wartime losses, “People must know that troops like the [Waffen] SS have to pay the butcher's bill more heavily than anyone else.”148 Hitler's statement, his willingness to deploy German troops into intense combat, and his slowness to maximize the number of legionnaire recruits are the opposite of what one would expect if minimizing citizen casualties was a primary goal. His private remarks in July 1941 that “for an elite force, like our SS, it's great luck to have suffered comparatively heavy losses” are similarly inconsistent with this alternative explanation.149

The German government's use and deployments of citizen troops in the Wehrmacht show that this tolerance for Reichsdeutsche casualties was not unique to the Waffen-SS. In late 1943, Hitler stated of German troops defending Crimea, “We're obliged, if it's even possible, to defend this second Stalingrad … we have to consider that the men [there] are [already] lost,” a position that contrasts with what one would expect if the preservation of German lives was a foremost concern.150 Likewise, if limiting Reichsdeutsche losses had been a primary driver, it is unlikely that German authorities would have passed on so many opportunities to recruit large numbers of legionnaires who could have done the fighting and the dying. To the contrary, the government did not fully loosen its restrictions on foreign enlistment until the final eighteen months of the war.

A fourth alternative explanation posits that a state could recruit foreigners when its population is “simply too small … to fill security force ranks.”151 But throughout World War II, the German government had more military-aged citizens whom it could have mobilized—including those in reserve service, in training, and in the factory. Potential citizen-recruits did exist; the government chose not to field them. Instead, it kept critical, skilled German workers on the production line well into the war. Authorities also eschewed proposals to maximize other options, such as conscripting women into the workforce—and thereby increasing its mobilized population—that could have freed men for military service. Germany also could have expanded the parameters of its recruitable citizenry, such as by widening the age groups eligible for mandatory service or permitting women to fight—options that the government eventually embraced, but only energetically after 1944.

Ultimately, attempts to explain legionnaire recruitment by focusing on a constant, such as population size, cannot explain the significant variation across cases, including Nazi Germany. After expanding with annexations in the 1930s, throughout the war Germany's citizen population did not significantly change beyond attrition from combat. Conversely, the government's beliefs about its need for troops and its political appetite to mobilize its citizenry for those troops varied widely over the course of the war. A focus on population size alone, without identifying the variables that shape how a government views that population—and how it is best used—cannot account for significant policy changes. Rather, as I argue, the confluence of demands for combat troops and the presence of specific factors that created constraints on citizen enlistment led Germany to make a political choice about how to use its population and, in turn, to begin or expand the recruitment of legionnaires.

This article has presented a supply-and-demand framework to explain why states recruit legionnaires. It framed new legionnaire recruitment as a response both to external territorial threats that amplify a state's need for combat troops and to domestic factors that raise the anticipated political risks that widened citizen recruiting could provoke. When states find themselves simultaneously threatened externally and constrained domestically, they are likely to enlist legionnaires as a tool to balance between these political and security pressures. In cases where the state's very existence is in jeopardy, its demand for troops becomes inelastic, and governments recruit legionnaires as a part of a strategy to maximize the manpower they can field for national defense. An evaluation of these claims against a large-N dataset, a review of multiple World War II combatants, and a detailed case study that presented a hard test for my theory all lend support to my argument. Conversely, this evidence provides little support to alternative arguments that posit that states recruit foreigners to foster ties to a diaspora or former colony, to acquire specialized expertise, to shield citizens from casualty, or to compensate for a small citizen population.

The argument has four key implications for scholarship. First, it calls for a reevaluation of the accuracy of existing narratives on the evolution of modern militaries. Although the recruitment of citizen-soldiers has proliferated across the globe, the recruitment of legionnaires has endured. Indeed, legionnaires remain a persistent feature of many contemporary armies. Second, it suggests that scholarship should prioritize examining how states expand the military manpower that they control directly, and that its focus on states’ use of private military and security companies may be, if not misguided, incomplete.152 Although contractors have flourished since the end of the Cold War, particularly in Afghanistan and Iraq, states still disproportionately use contractors in support functions rather than in combat roles. While the availability of contractors shapes how states prepare for and sustain their wars, legionnaires play a more central and more consequential role in how those governments actually fight the conflicts they enter. Third, legionnaire recruitment has implications for scholarship on net assessments.153 Rather than a fixed or an easily discernable quantity, a state's pool of potential soldiers can be far larger than the number that its citizenry alone suggests. Scholars and policymakers thus face the daunting but vital task of determining how to adjust calculations of force-to-force ratios and total combat potential to account for legionnaire recruiting. Fourth, the recruitment of legionnaires complicates arguments that link regime type to variation in combat effectiveness, and particularly those that privilege culture or values to explain battlefield success. For example, some scholars have argued that democracies are successful in war partly because their troops are inculcated with democratic norms that favor individual initiative, or because their soldiers see their governments as legitimate.154 In cases where a substantial proportion of a state's troops come from countries lacking democratic norms, scholarship must consider at what thresholds these claims no longer hold.

The use of legionnaires in wartime has significance for policymakers as well, given the tangible implications for how states implement, sustain, and select their security strategies. States that exert significant influence internationally, such as the United States and Russia, are among those that currently enlist legionnaires, and states that recruit them are using legionnaires to fight and shape the world's ongoing conflicts. In September 2020, Turkey reportedly deployed Syrian legionnaire recruits to Azerbaijan amid Baku's hostilities with Armenia, and similar reports have shadowed Turkey's involvement in Libya.155 In August 2020, the Indian government sent a pointed signal to Chinese leadership by publicizing the surge of India's Tibetan-staffed legionnaire unit, the Special Frontier Force, to disputed areas along their border.156

To a degree, policymakers recognize the advantages that legionnaire recruitment can provide, because governments are putting this policy into practice. The continuing use of these troops is cause for caution, however. Practitioners must be aware that opponents will enlist soldiers from abroad, with tangible consequences for that adversary's ability to inflict surprise, conduct expeditionary operations, or intervene militarily. For states or their allies that already enlist legionnaires or that are considering doing so, decisionmakers must be watchful for indications that these policies could feed interventionist or casualty-tolerant agendas.

Legionnaires also can enable governments to mobilize battle-tested or highly skilled recruits into their armed forces, without needing to invest in long training pipelines or participating in conflicts abroad; the Tibetan Special Frontier Force, for example, helped swiftly buttress India's mountain warfare capabilities. The ability of states to recruit legionnaires thus requires that policymakers adjust their military planning to incorporate broader and more creative ideas about what strategic surprise from an adversary could look like. Military planning should not only consider when and where an adversary could initiate hostilities, but also account for the possibility that unexpected numbers of soldiers, or unexpected types of fighting, could be a part of that war effort. Governments also should be attentive to where their adversaries are seeking to build new diplomatic inroads, inasmuch as states could seek to facilitate their legionnaire recruitment efforts by cultivating influence or providing incentives to peer states that are open to their citizens joining foreign militaries.

At its heart, the recruitment of legionnaires makes it possible for states to engineer rapid changes in the quality and/or quantity of a core component of national power—combat personnel. Such changes provide states far more political and practical flexibility in conducting military operations than does relying on citizens alone. Recruiting legionnaires thus can enable states to sustain operations beyond the capacity of their citizenries. Moreover, by providing states a rapid way to augment their combat strength, legionnaires can increase a government's ability to achieve strategic surprise against an adversary.

This article has sought to reframe how scholarship understands the strategies that states employ to buttress their capacity for war. To the extent that military manpower has been traditionally discussed in autarkic terms—bound to a state's territory and citizenry—legionnaire recruitment demonstrates how readily governments reach beyond their borders to secure the resources that enable them to pursue their national aims. Insofar as sufficient material capabilities are the sine qua non of a government's ability to act on its interests and ambitions, understanding how states buttress key pillars of their military power is of vital consequence.

The author is especially grateful to Austin Carson, Alexander Downes, Yonatan Lupu, David Malet, and Harris Mylonas for their invaluable advice and comments. The author also wishes to thank Nir Arielli, Alexis Blanc, Lindsay Cohn, Jonathan Hack, Kendrick Kuo, Aparna Ravi, participants of the Triangle Institute for Security Studies New Faces Conference, participants of the George Washington University International Relations Research Retreat, and the anonymous reviewers for their comments and suggestions on earlier drafts. The views expressed here are solely those of the author and do not reflect the official policy of the U.S. Government


Quoted in David M. Glantz, Helmut Heiber, and Adolf Hitler, Hitler and His Generals: Military Conferences 1942–1945: The First Complete Stenographic Record of the Military Situation Conferences, from Stalingrad to Berlin (New York: Enigma, 2003), p. 738.


Elizabeth M.F. Grasmeder, “Brothers in Arms: Foreign Legions, National Armies, and Re-examining Citizenship and Military Service,” Ph.D. dissertation, George Washington University, 2020.


This article uses the terms “enlist,” “recruit,” and “mobilize” interchangeably, always referring to the incorporation of new individuals into a state's military and uniformed services. It uses the term “foreigner” always referring to individuals who adhere to the definition of legionnaire.


Deborah Avant, “From Mercenary to Citizen Armies: Explaining Change in the Practice of War,” International Organization, Vol. 54, No. 1 (Winter 2000), pp. 41–72, doi.org/10.1162/002081800551118; Barry R. Posen, “Nationalism, the Mass Army, and Military Power,” International Security, Vol. 18, No. 2 (Fall 1993), pp. 80–124, doi.org/10.2307/2539098; Janice E. Thomson, “State Practices, International Norms, and the Decline of Mercenarism,” International Studies Quarterly, Vol. 34, No. 1 (March 1990), pp. 23–47, doi.org/10.2307/2600404; and Janice E. Thomson, Mercenaries, Pirates, and Sovereigns: State-Building and Extraterritorial Violence in Early Modern Europe (Princeton, N.J.: Princeton University Press, 1994).


Others include Australia, Bahrain, Belgium, Bolivia, Brunei, Canada, Chad, Denmark, Eritrea, France, Ireland, Kuwait, Luxembourg, Monaco, New Zealand, Norway, Oman, Qatar, Saudi Arabia, Serbia, Singapore, Spain, Sudan, Syria, Ukraine, the United Arab Emirates, and the United Kingdom.


Posen, “Nationalism.”


Edward A. Shils and Morris Janowitz, “Cohesion and Disintegration in the Wehrmacht in World War II,” Public Opinion Quarterly, Vol. 12, No. 2 (Summer 1948), pp. 280–315, doi.org/10.1086/265951; Stephen G. Fritz, “‘We Are Trying … to Change the Face of the World’—Ideology and Motivation in the Wehrmacht on the Eastern Front: The View from Below,” Journal of Military History, Vol. 60, No. 4 (October 1996), pp. 683–710, doi.org/10.2307/2944661; and Omer Bartov, Hitler's Army: Soldiers, Nazis, and War in the Third Reich (Oxford: Oxford University Press, 1991).


Sarah V. Percy, “Mercenaries: Strong Norm, Weak Law,” International Organization, Vol. 61, No. 2 (April 2007), p. 371, doi.org/10.1017/S0020818307070130.


Thomson, “State Practices,” p. 27.


Nir Arielli, From Byron to Bin Laden: A History of Foreign War Volunteers (Cambridge, Mass.: Harvard University Press, 2018); Kristin M. Bakke, “Help Wanted? The Mixed Record of Foreign Fighters in Domestic Insurgencies,” International Security, Vol. 38, No. 4 (Spring 2014), pp. 150–187, doi.org/10.1162/ISEC_a_00156; and David Malet, Foreign Fighters: Transnational Identity in Civil Conflicts (Oxford: Oxford University Press, 2013).


Ilya Berkovich, Motivation in War: The Experience of Common Soldiers in Old-Regime Europe (Cambridge: Cambridge University Press, 2017); Christopher L. Brown and Philip D. Morgan, eds., Arming Slaves: From Classical Times to the Modern Age (New Haven, Conn.: Yale University Press, 2006); John Laband, “The Slave Soldiers of Africa,” Journal of Military History, Vol. 81, No. 1 (January 2017), pp. 9–38; and Daniel Pipes, “The Strategic Rationale for Military Slavery,” Journal of Strategic Studies, Vol. 2, No. 1 (1979), pp. 34–46, doi.org/10.1080/01402397908437012.


Cynthia H. Enloe, Ethnic Soldiers: State Security in Divided Societies (Athens: University of Georgia Press, 1980); Donald L. Horowitz, Ethnic Groups in Conflict (Los Angeles: University of California Press, 1985), pp. 549–551; and Jason Lyall, Divided Armies: Inequality and Battlefield Performance in Modern War (Princeton, N.J.: Princeton University Press, 2020).


Thomson, “State Practices,” pp. 27, 29. Thomson declines to elaborate further on size or type of manpower shortages that could spur foreign recruitment.


Kolby Hanson and Erik Lin-Greenberg, “Noncitizen Soldiers: Explaining Foreign Recruitment by Modern State Militaries,” Security Studies, Vol. 28, No. 2 (2019), pp. 286–320, doi.org/10.1080/09636412.2019.1551571.


Ibid., pp. 307–308.


Stephen G. Brooks and William C. Wohlforth, “Power, Globalization, and the End of the Cold War: Reevaluating a Landmark Case for Ideas,” International Security, Vol. 25, No. 3 (Winter 2000/01), pp. 5–53, doi.org/10.1162/016228800560516; Richard Price, “Reversing the Gun Sights: Transnational Civil Society Targets Land Mines,” International Organization, Vol. 52, No. 3 (Summer 1998), pp. 613–644, doi.org/10.1162/002081898550671; Nina Tannenwald, “The Nuclear Taboo: The United States and the Normative Basis of Nuclear Non-Use,” International Organization, Vol. 53, No. 3 (Summer 1999), pp. 433–468, doi.org/10.1162/002081899550959; and Ward Thomas, “Norms and Security: The Case of International Assassination,” International Security, Vol. 25, No. 1 (Summer 2000), pp. 105–133, doi.org/10.1162/016228800560408.


Lyall, Divided Armies; James T. Quinlivan “Coup-Proofing: Its Practice and Consequences in the Middle East,” International Security, Vol. 24, No. 2 (Fall 1999), pp. 131–165, doi.org/10.1162/016228899560202; and Caitlin Talmadge, The Dictator's Army: Battlefield Effectiveness in Authoritarian Regimes (Ithaca, N.Y.: Cornell University Press, 2015).


Colonial and imperial troops are, therefore, not legionnaires.


U.S. Joint Chiefs of Staff, Multinational Operations, Joint Publication 3-16 (Washington, D.C.: Government Printing Office [GPO], 2019), p. x, https://www.jcs.mil/Portals/36/Documents/Doctrine/pubs/jp3_16pa.pdf?ver=Z2GObyi_wW55p7kQZG07Q%3D%3D.


The term “mercenary” (or “contractor”) applies equally for citizens and noncitizens, provided that they fit this description.


U.S. Army, Contractors on the Battlefield, Field Manual 3-100.21 (Washington, D.C.: GPO, 2003), p. 1-7, https://fas.org/irp/doddir/army/fm3-100-21.pdf.


Throughout this article, I use the phrase “new legionnaire recruitment” and similar formulations as shorthand to refer to these values of the dependent variable.


Given these dynamics, my theory anticipates that states with an inelastic demand for manpower also would expand their recruitment of citizens for soldiers.


Carl von Clausewitz, On War, ed. and trans. Michael Howard and Peter Paret (Princeton, N.J.: Princeton University Press, 1976), p. 592.


On the drawbacks of conscription, see Walter Y. Oi, “The Economic Cost of the Draft,” American Economic Review, Vol. 57, No. 2 (May 1967), pp. 39–62, https://www.jstor.org/stable/1821607; W. Lee Hansen and Burton A. Weisbrod, “Economics of the Military Draft,” Quarterly Journal of Economics, Vol. 81, No. 3 (August 1967), pp. 395–421, doi.org/10.2307/1884808; and Kenneth Scheve and David Stasavage, “The Conscription of Wealth: Mass Warfare and the Demand for Progressive Taxation,” International Organization, Vol. 64, No. 4 (October 2010), pp. 529–561, doi.org/10.1017/S0020818310000226.


During periods of colonialism, I would include imperial subjects as a part of this primary national manpower supply.


This also can arise in countries with ethnic cleavages. See Philip Roessler, “The Enemy Within: Personal Rule, Coups, and Civil War in Africa,” World Politics, Vol. 63, No. 2 (April 2011), p. 305, doi.org/10.1017/S0043887111000049.


Lyall, Divided Armies. On core and noncore groups, see Harris Mylonas, The Politics of Nation-Building: Making Co-Nationals, Refugees, and Minorities (Cambridge: Cambridge University Press, 2013).


On the link between domestic labor markets and citizen recruiting, see Lindsay P. Cohn and Nathan W. Toronto, “Markets and Manpower: The Political Economy of Compulsory Military Service,” Armed Forces & Society, Vol. 43, No. 3 (July 2017), pp. 436–458, doi.org/10.1177/0095327X16667086.


Depending on the value of the domestic variable I identify, progressively higher threat perceptions also can spur greater citizen enlistment, even as new legionnaire policies emerge.


See Steven R. David, Choosing Sides: Alignment and Realignment in the Third World (Baltimore, Md.: Johns Hopkins University Press, 1991); and Steven R. David, “Explaining Third World Alignment,” World Politics, Vol. 43, No. 2 (January 1991), pp. 233–256, doi.org/10.2307/2010472.


On before-after design, see Alexander L. George and Andrew Bennett, Case Studies and Theory Development in the Social Sciences (Cambridge, Mass.: MIT Press, 2005), pp. 166–167.


On deconstructing a single case into subcases, see John Gerring, “What Is a Case Study and What Is It Good For?” American Political Science Review, Vol. 98, No. 2 (May 2004), pp. 341–354, doi.org/10.1017/S0003055404001182; and Peter A. Hall, “Aligning Ontology and Methodology in Comparative Politics,” in James Mahoney and Dietrich Rueschemeyer, eds., Comparative Historical Analysis in the Social Sciences (Cambridge: Cambridge University Press, 2003), p. 395.


The online appendix is available at doi.org/10.7910/DVN/U8GLNS.


During civil wars, I record recruitment only by the incumbent, unless regime change occurred.


This alternative minimum allows for confirmable cases during short wars. For instance, Finland's Winter War lasted five months, but fielded more than 12,000 legionnaires. It does, however, exclude isolated “acts of recruitment,” such as if a government were to provide a one-time dispensation permitting the entirety of foreign insurgents it had sponsored to enlist in the military.


Most recruitment policies raised far more troops, and just two cases in the dataset skirt this minimum cumulative threshold: Israel's recruitment of non-Jewish volunteers in 1967 and Mali's recruitment of Russian pilots and aircrew in 1961.


My definition of legionnaires excludes policies like Cyprus's, in which states recruit from their ethnic diasporas, or Israel's, wherein the government views foreign coreligionists as citizens.


The data do not enable evaluation of arguments about foreign recruitment as a tool to mitigate civilian casualties, although I engage this explanation in the case study.


For information on the subsequent naturalization of these troops, see Catherine N. Barry, New Americans in Our Nation's Military: A Proud Tradition and Hopeful Future (Washington, D.C.: Center for American Progress, November 8, 2013), https://www.americanprogress.org/issues/immigration/reports/2013/11/08/79116/new-americans-in-our-nations-military/.


Andrew Mambo and Julian Schoefield, “Military Diversion in the 1978 Uganda-Tanzania War,” Journal of Political and Military Sociology, Vol. 35, No. 2 (Winter 2007), p. 308.


Military Capabilities of the Smaller Persian Gulf States (Washington, D.C.: Central Intelligence Agency, August 1984), pp. 17–19, CIA Freedom of Information Act (FOIA) Electronic Reading Room, https://www.cia.gov/readingroom/docs/CIA-RDP85T00314R000200090002-0.pdf.


Douglas Porch, The French Foreign Legion: A Complete History of the Legendary Fighting Force (New York: Skyhorse, 2010).


Richard M. Gibson and Wenhua Chen, The Secret Army: Chiang Kai-Shek and the Drug Warlords of the Golden Triangle (Singapore: John Wiley (Asia), 2011).


Henry A. Gill III, Soldier under Three Flags: The Exploits of Special Forces Captain Larry A. Thorne (Ventura, Calif.: Pathfinder, 1998); James J. Carafano, “Mobilizing Europe's Stateless: America's Plan for a Cold War Army,” Journal of Cold War Studies, Vol. 1, No. 2 (Spring 1999), pp. 61–85, https://www.jstor.org/stable/26925016; Susan L. Carruthers, “Between Camps: Eastern Bloc ‘Escapees’ and Cold War Borderlands,” American Quarterly, Vol. 57, No. 3 (September 2005), pp. 911–942, https://www.jstor.org/stable/40068321; Alison F. Atkins, “From a Dream to a Reality Check: Protecting the Rights of Tomorrow's Conditional Legal Resident Enlistees,” Military Law Review, Vol. 216 (2013), pp. 12–13; and James Stejskal, Special Forces Berlin: Clandestine Cold War Operations of the US Army's Elite, 1956–1990 (Havertown, Pa.: Casemate, 2017).


Babak Dehghanpisheh, “Iran Recruits Pakistani Shi'ites for Combat in Syria,” Reuters, December 10, 2015, https://www.reuters.com/article/us-mideast-crisis-syria-pakistan-iran/iran-recruits-pakistani-shiites-for-combat-in-syria-idUSKBN0TT22S20151210; and Hashmatallah Moslih, “Iran ‘Foreign Legion’ Leans on Afghan Shia in Syria War,” Al-Jazeera, January 22, 2016, https://www.aljazeera.com/news/2016/1/22/iran-foreign-legion-leans-on-afghan-shia-in-syria-war.


Contemporaneous conflicts also featured legionnaire recruitment, including Finland during the Winter War and Continuation War, and Chinese Nationalists during and after the Second Sino-Japanese War.


“National Material Capabilities,” Version 4, The Correlates of War Project; and J. David Singer, Stuart Bremer, and John Stuckey, “Capability Distribution, Uncertainty, and Major Power War, 1820–1965,” in Bruce M. Russett, ed., Peace, War, and Numbers (Beverly Hills, Calif.: Sage, 1972), pp. 19–48.


Quoted in Julian Jackson, The Fall of France: The Nazi Invasion of 1940 (Oxford: Oxford University Press, 2004), p. 9.


Thomas Christofferson and Michael S. Christofferson, France during World War II: From Defeat to Liberation (New York: Fordham University Press, 2006), p. 20; and Saul K. Padover, “France in Defeat: Causes and Consequences,” World Politics, Vol. 2, No. 3 (April 1950), p. 308; doi.org/10.2307/2008907.


Michael Alfred Peszke, “The Polish Armed Forces in Exile: Part 1—September 1939–July 1941,” Polish Review, Vol. 26, No. 1 (1981), pp. 85–88, https://www.jstor.org/stable/25777807.


Britain also used the manpower of “governments-in-exile,” leveraging these personnel through a range of means—including recruiting some as legionnaires or, in others, partnering in a coalition or allied capacity. British Dominions also recruited legionnaires. For more, see Government of New Zealand, Order in Council, “The Alien Enlistment Emergency Regulations 1939—Serial No. 1939/281,” Wellington, New Zealand, December 20, 1939, http://www.nzlii.org/nz/legis/num_reg/aeer1939373/; Rachel Lea Heide, “Allies in Complicity: The United States, Canada, and the Clayton Knight Committee's Clandestine Recruiting of Americans for the Royal Canadian Air Force, 1940–1942,” Journal of the Canadian Historical Association, Vol. 15, No. 1 (2004), pp. 207–230, doi.org/10.7202/012074ar; and Daniel Leach, “The Other Allies: Military Security, National Allegiance, and the Enlistment of ‘Friendly Aliens’ in the Australian Armed Forces, 1939–45,” War & Society, Vol. 32, No. 1 (March 2013), pp. 26–48, doi.org/10.1179/0729247312Z.00000000015.


“Refugees,” House of Commons Debate (HC Deb), Vol. 362, col. 1278, July 10, 1940, Hansard 1803–2005, http://hansard.millbanksystems.com/commons/1940/jul/10/refugees-1.


“Aliens (Enlistment),” HC Deb, Vol. 365, col. 1176, November 5, 1940, Hansard 1803–2005, https://api.parliament.uk/historic-hansard/commons/1940/nov/05/aliens-enlistment.


Quoted in Michael S. Goodman, “In Search of a Lost Commando: A Personal Account of No. 3 ‘X’ Troop, No. 10 Inter-Allied Commando,” Journal of Intelligence History, Vol. 15, No. 1 (2016), p. 44, doi.org/10.1080/16161262.2015.1104978.


Helen Fry, Churchill's German Army: The Germans Who Fought for Britain in World War Two (London: History, 2010).


Soviet General Staff, The Battle of Moscow, 1941–1942: The Red Army's Defensive Operations and Counteroffensive along the Moscow Strategic Direction, ed. and trans. Richard W. Harrison (Solihull, UK: Helion, 2015), p. 68.


Helmuth Greiner and Percy Ernst Schramm, eds., Kriegstagebuch des Oberkommandos der Wehrmacht (Wehrmachtführungsstab) 1940–1945 [War diary of the Wehrmacht High Command (Wehrmacht command staff)], 4 Vols. (Frankfurt: Bernard and Graefe Verlag für Wehrwesen, 1961–1965), p. 1075; and Czesław K. Grzelak et al., Armia Berlinga i Żymierskiego: Wojsko Polskie na Froncie Wschodnim 1943–1945 [Berling and Zymierski's army: Polish army on the Eastern Front, 1943–1945] (Warsaw: Neriton, 2002). Some Soviet-recruited Poles fought in new formations, such as the Anders and Berling Armies, whereas others were pressed into existing Soviet units.


Although U.S. legionnaire recruitment measures in 1942 and 1943 arose as citizen labor grew scarcer and combat escalated—conforming to my argument's expectations—the recruitment policy of 1940 represents a compelling puzzle for future investigation that does not, at first glance, conform to the expectations of my argument.


Charles E. Roh and Frank K. Upham, “The Status of Aliens under United States Draft Laws,” Harvard International Law Journal, Vol. 13, No. 3 (Summer 1972), p. 503.


Not all foreigners who enlisted accepted this incentive. Legionnaires that naturalized would cease to be categorized as legionnaires and, instead, constitute citizen-soldiers. Foreigners that served in the military, but completed naturalization at a later date, are coded as legionnaires during the time of their service.


Quoted in Brunello Mantelli, “L'Emigrazione di Braccianti Italiani nel Terzo Reich (1938–1943)” [The emigration of Italian laborers to the Third Reich (1948–1943)], Studi Storci, Vol. 31, No. 3 (July–September 1990), p. 747, https://www.jstor.org/stable/20565411.


Stefano Fabei, La Legione Straniera di Mussolini [Mussolini's Foreign Legion] (Milan: Mursia, 2008), p. 8; and Romain H. Rainero, I Reparti Arabi e Indiani Dell'Esercito Italianio Nella Seconda Guerra Mondiale (“La Frecce Rosse”) [Arab and Indian units of the Italian army in the Second World War (“The Red Arrows”)] (Rome: Stato Maggiore Dell'esercito Ufficio Storico, 2007), p. 245.


Fabei, La Legione, p. 51.


Alberto Becherelli, Italia e Stato Indipendente Croato (1941–1943) [Italy and the independent state of Croatia, (1941–1943)] (Rome: Edizioni Nuova Cultura, 2012), pp. 209, 216; and Eric Gobetti, Alleati del Nemico: L'Occupazione Italiana in Jugoslavia (1941–1943) [Allies of the enemy: the Italian occupation of Yugoslavia (1941–1943)] (Roma: Laterza, 2013), p. 76.


Paul H. Kratoska, “Labor Mobilization in Japan and the Japanese Empire,” in Paul H. Kratoska, ed., Asian Labor in the Wartime Japanese Empire: Unknown Histories (Singapore: National University of Singapore Press, 2006), pp. 8–9.


Quoted in Kaori Maekawa, “The Heiho during the Japanese Occupation of Indonesia,” in Kratoska, ed., Asian Labor in the Wartime Japanese Empire, p. 183.


Joyce C. Lebra, Japanese-Trained Armies in Southeast Asia (Hong Kong: Heinemann Asia, 1977), pp. 97–98, 103; Maekawa, “Heiho,” pp. 179–196; and George McTurnan Kahin, Nationalism and Revolution in Indonesia (Ithaca, N.Y.: Cornell University Press, 2003), pp. 109–110.


Quoted in Maekawa, “Heiho,” p. 179.


Between restarting the draft in 1935 and spring 1940, Germany conformed to what I code as perceiving low threats externally and facing low constraints in recruiting domestically. Consistent with my theory, the German government pursued expansive citizen enlistment without legionnaire recruitment.


George H. Stein, The Waffen SS: Hitler's Elite Guard at War, 1939–1945 (Ithaca, N.Y.: Cornell University Press, 1984), p. 23.


“The Soldier Friend-Pocket Diary for the German Armed Forces-Edition D: Waffen SS (2825-PS),” Collection of Documentary Evidence and Guide Materials Prepared by the American and British Prosecuting Staffs for Presentation before the International Military Tribunal at Nuremberg, Germany, Vol. 2, chap. 15, pt. 5 (Washington, D.C.: GPO, 1947), p. 183, https://www.loc.gov/law/mlr/pdf/NT_Nazi_Vol-II.pdf; and Greiner and Schramm, Kriegstagebuch, pp. 64, 66–67.


Adolf Hitler, Hitler's Table Talk, 1941–1944: His Private Conversations, trans. Norman Cameron and R.H. Stevens (New York: Enigma, 2000), pp. 129–130.


Hitler, Table Talk, p. 175.


“National Material Capabilities,” Version 4; and Singer, Bremer, and Stuckey, “Capability Distribution, Uncertainty, and Major Power War, 1820–1965.”


Quoted in Roderick Stackelberg and Sally A. Winkle, eds., The Nazi Germany Sourcebook: An Anthology of Texts (London: Routledge, 2002), p. 199.


Hitler, Table Talk, p. 305. Most World War I combatants recruited legionnaires.


Ibid., pp. 327–328.


Burton Klein, “Germany's Preparation for War: A Re-examination,” American Economic Review, Vol. 38, No. 1 (March 1948), p. 70, https://www.jstor.org/stable/1801938; and Richard Overy, “Unemployment in the Third Reich,” Business History, Vol. 29, No. 3 (1987), p. 264, doi.org/10.1080/00076798700000054.


Edward L. Homze, Foreign Labor in Nazi Germany (Princeton, N.J.: Princeton University Press, 1967), pp. 5–10.


William Jeffress Fanning Jr., “The German War Economy in 1941: A Study of Germany's Material and Manpower Problems in Relation to the Overall Military Effort,” Ph.D. dissertation, Texas Christian University, 1983, pp. 157–158.


Rolf-Dieter Müller, Hitler's Wehrmacht, 1935–1945, trans. Janice W. Ancker (Lexington: University Press of Kentucky, 2016), p. 142; and Richard Overy, War and Economy in the Third Reich (Oxford: Clarendon, 1994), p. 279.


Fanning, “War Economy,” p. 47.


Quoted in ibid., p. 53.


Bundesarchiv (BArch), RW 19/99, OKW/WiRüAmt, “Kriegswirtschaftlicher Lagebericht Nr. 25 September 1941” [German Federal Archives, Reichswehr and Wehrmacht (1919 to 1945/1946) 19/99, High Command of the Wehrmacht/Defense and Armaments Office, “War Economic Situation Report No. 25 September 1941], October 10, 1941, pp. 1–2; and Fanning, “War Economy,” p. 165.


Quoted in Peter Longerich, Hitler: A Biography, trans. Jeremy Noakes and Lesley Sharpe (Oxford: Oxford University Press, 2019), p. 688.


Although Germany's allies provided considerable manpower, these same allies at times imposed new demands on German soldiers and difficulties on German war efforts. For example, the disastrous performance of Italian forces in Southeastern Europe and North Africa forced Berlin to divert significant resources to save its flailing ally—sending troops to occupy Yugoslavia and Greece and dispatching the Afrika Korps across the Mediterranean.


Rüdiger Overmans, Deutsche Militärische Verluste im Zweiten Weltkrieg [German miltiary losses in World War II] (Munich: Oldenbourg Verlag, 1999), p. 266.


Omer Bartov, The Eastern Front, 1941–45: German Troops and the Barbarisation of Warfare (New York: St. Martin's, 1986), p. 40; and Müller, Hitler's Wehrmacht, p. 175.


Quoted in James Steiner, Hitler's Wehrmacht: German Armed Forces in Support of the Führer (Jefferson, N.C.: McFarland, 2008), p. 77.


Chris Bishop, SS: Hitler's Foreign Divisions: Foreign Volunteers in the Waffen-SS 1940–1945 (London: Amber, 2005), p. 11.


Ibid., p. 12.


Kenneth Estes, A European Anabasis: Western European Volunteers in the German Army and SS, 1940–45 (Solihull, UK: Helion, 2015), pp. 52–53.


Quoted in Bartov, Eastern Front, p. 111.


Quoted in John Robert Stovall, “Gottlob Berger and Waffen-SS Recruiting Policies,” Ph.D. dissertation, University of Colorado, 1976, p. 146.


Hitler, Table Talk, p. 121.


BArch, RW 19/99, OKW/WiRüAmt, “Kriegswirtschaftlicher Lagebericht Nr. 27 November 1941” [German Federal Archives, Reichswehr and Wehrmacht (1919 to 1945/1946) 19/99, High Command of the Wehrmacht/Defense and Armaments Office, “War Economic Situation Report No. 27 November 1941”]. December 10, 1941, p. 2; and Fanning, “War Economy,” pp. 165–166.


Quoted in Glantz, Heiber, and Hitler, Hitler, p. 104.


Homze, Foreign Labor.


Fanning, “War Economy,” p. 171.


“Bormann's Circular of May 5, 1943 with a Leaflet on the General Principles for the Treatment of Foreign Workers in the Reich (Evidence GB-538),” in Trial of the Major War Criminals before the International Military Tribunal, Nuremberg, November 14, 1945–October 1, 1946, Vol. 25 (Nuremberg: International Military Tribunal, 1947), doc.205-PS, p. 299, https://www.loc.gov/rr/frd/Military_Law/pdf/NT_Vol-XXV.pdf (emphasis in the original).


Hitler, Table Talk, p. 168.


Bartov, Eastern Front, pp. 123–126.


Quoted in Glantz, Heiber, and Hitler, Hitler, p. 263.


Quoted in ibid., pp. 306–307.


Hitler, Table Talk, p. 25.


“Top Secret Memorandum by Rosenberg on His Discussion with Hitler on December 14, 1941 (Exhibit USA-824),” in Trial of the Major War Criminals, Vol. 27 (Nuremberg: International Military Tribunal, 1948), doc. 1517-PS, p. 272, https://www.loc.gov/rr/frd/Military_Law/pdf/NT_Vol-XXVII.pdf.


Bartov, Eastern Front, pp. 138–139.


Müller, Hitler's Wehrmacht, p. 78.


Germany's Soviet recruits were organized across units that carried different designations, including Hilfswillige, Ostbataillone, Osteinheiten, Ostlegionen, and Osttruppen. Some units comprising Turkic-speaking recruits from the Soviet Union were designated as Turk- rather than as Ost- formations; in other cases, German documents labeled these and other foreign formations as Freiwillige.


Quoted in George Fischer, Soviet Opposition to Stalin: A Case Study in World War II (Cambridge, Mass.: Harvard University Press, 1952), p. 46.


Quoted in ibid., p. 47.


Mark Edele, Stalin's Defectors: How Red Army Soldiers became Hitler's Collaborators, 1941–1945 (Oxford: Oxford University Press, 2017), pp. 129–132.


Quoted in ibid., pp. 125–126.


Quoted in Stovall, “Berger,” p. 9.


Edele, Defectors, pp. 132–133.


Quoted in Edgar Erwin Knoebel, “Racial Illusion and Military Necessity: A Study of SS Political and Manpower Objectives in Occupied Belgium,” Ph.D. dissertation, University of Colorado, 1965, pp. 87–88.


Hitler, Table Talk, p. 9.


Stovall, “Berger,” p. 147.


Hitler, Table Talk, p. 202.


Estes, Anabasis, p. 126.


Glantz, Heiber, and Hitler, Hitler, p. 306.


Quoted in ibid., p. 338.


Quoted in ibid., p. 341.


Quoted in ibid., pp. 442–443.


Quoted in ibid., p. 443. The Soviet victory in Operation Bagration in the summer of 1944 was so costly to German manpower that just sixteen German divisions remained between Berlin and roughly 160 Soviet divisions advancing toward the capital.


Quoted in ibid., p. 501.


Quoted in ibid., p. 554.


Quoted in ibid., p. 695.


Quoted in David K. Yelton, “‘Ein Volk Steht Auf’: The German Volkssturm and Nazi Strategy, 1944–45,” Journal of Military History, Vol. 64, No. 4 (October 2000), p. 1070, doi.org/10.2307/2677267.


Estes, Anabasis, p. 151; and Robert Arthur Gelwick, “Personnel Policies and Procedures of the Waffen-SS,” Ph.D. dissertation, University of Nebraska, 1971, p. 597.


“Affidavit General Staff and OKW-1179, 5 July 1946, by Freiherr von Lüdinghausen,” in Trial of the Major War Criminals, Vol. 42 (Nuremberg: International Military Tribunal, 1949), document Genst.(A)-1179, pp. 266–267, https://www.loc.gov/rr/frd/Military_Law/pdf/NT_Vol-XLII.pdf; and “Affidavit General Staff and OKW-1200, 5 July 1946, by the former Colonel GSC Wolfgang Ruhsert,” in Trial of the Major War Criminals, Vol. 42, doc. Genst.(A)-1200, p. 269, https://www.loc.gov/rr/frd/Military_Law/pdf/NT_Vol-XLII.pdf.


Gelwick, “Policies,” pp. 625–628; and Stovall, “Berger,” pp. 130–131.


Gelwick, “Policies,” pp. 597–600.


Hitler, Table Talk, p. 305.


Quoted in Knoebel, “Illusion,” p. 91.


Quoted in Fischer, Soviet Opposition, p. 186.


Ibid., pp. 77–78.


Stovall, “Berger,” p. 148.


Hanson and Lin-Greenberg, “Noncitizen Soldiers,” p. 314; and Thomson, “State Practices,” p. 27.


Hanson and Lin-Greenberg, “Noncitizen Soldiers,” p. 314.


Gelwick, “Policies,” p. 596; and Stovall, “Berger,” p. 117.


Hanson and Lin-Greenberg, “Noncitizen Soldiers,” pp. 301–306; and Thomson, “State Practices,” p. 29.


Fischer, Soviet Opposition, p. 46.


“Affidavit General Staff and OKW-1200,” in Trial of the Major War Criminals, Vol. 42, doc. Genst.(A)-1200, p. 269; and “War Diary of the German Main Liaison Staff,” in Trial of the Major War Criminals, Vol. 37 (Nuremberg: International Military Tribunal, 1949), doc. 257-F, p. 84, https://www.loc.gov/rr/frd/Military_Law/pdf/NT_Vol-XXXVIII.pdf.


Fischer, Soviet Opposition, p. 186.


Hanson and Lin-Greenberg, “Noncitizen Soldiers,” p. 308.


Hitler, Table Talk, pp. 129–130.


Ibid., p. 13.


Quoted in Glantz, Heiber, and Hitler, Hitler, p. 341.


Hanson and Lin-Greenberg, “Noncitizen Soldiers,” p. 307. The authors do not specify what size population would trigger this response.


P.W. Singer, Corporate Warriors: The Rise of the Privatized Military Industry (Ithaca, N.Y.: Cornell University Press, 2003); Deborah D. Avant, The Market for Force: The Consequences of Privatizing Security (Cambridge: Cambridge University Press, 2005); Percy, “Mercenaries”; and Caroline Varin, Mercenaries, Hybrid Armies, and National Security: Private Soldiers and the State in the 21st Century (New York: Routledge, 2015).


See Eliot A. Cohen, “Toward Better Net Assessment: Rethinking the European Conventional Balance,” International Security, Vol. 13, No. 1 (Summer 1988), pp. 50–89, doi.org/10.2307/2538896; John J. Mearsheimer, “Why the Soviets Can't Win Quickly in Central Europe,” International Security, Vol. 7, No. 1 (Summer 1982), pp. 3–39, doi.org/10.2307/2538686; and Barry R. Posen, “Measuring the European Conventional Balance: Coping with Complexity in Threat Assessment,” International Security, Vol. 9, No. 3 (Winter 1984/85), pp. 47–88, doi.org/10.2307/2538587.


Dan Reiter and Allan C. Stam, Democracies at War (Princeton, N.J.: Princeton University Press, 2002).


Seth J. Frantzman, “Evidence Mounts that Turkey Recruited Syrians to Fight Armenia,” Jerusalem Post, September 30, 2020, https://www.jpost.com/middle-east/evidence-mounts-that-tur-key-recruited-syrians-to-fight-armenia-644078; and “Pentagon Says Turkey Sent 3,500 Syrian Fighters to Back Libyan Government,” Radio Free Europe Radio Liberty, July 18, 2020, https://www.rferl.org/a/pentagon-turkey-3-500-syrian-fighters-libya-russia/30734486.html.


Rezaul H. Laskar and Sutirtho Patranobis, “China Carrying Out Drives to Recruit Tibetans Amid Border Standoff with India,” Hindustan Times, April 17, 2021, https://www.hindustantimes.com/world-news/pla-conducting-special-drives-to-recruit-more-tibetans-amid-lac-standoff-101618677562088.html.