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Publications and Works in Progress

Leaning on Legionnaires:
Why Modern States Recruit Foreign Soldiers

International Security (July 2021), Vol. 46, No. 1, pp. 147-195.

Winner of the American Political Science Association (APSA) Catherine McArdle Kelleher Award for Best International Security Article of 2022.

Winner of the International Studies Association Security Studies Section Best Article Award of 2022.

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. I evaluate these claims using a multimethod approach, 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 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.


Works Under Review

“Fighting to Survive: How States Adapt to Battle Existential Threats”

Fatmiyoun near Aleppo_edited.jpg

Works in Progress

Introducing the Foreign Recruitment Dataset:

Legionnaires and the Spectrum of Military Manpower

Security Arbitrage:

Why States Support an Ally's Covert Action

Needs Must:

Turning to Enemies for Soldiers

In Cause of Country:

How States Defend Their Legionnaire Recruitment

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