Existing theories of combat motivation and military effectiveness largely dismiss the utility of coercing one's own soldiers to fight. Yet nearly 20 percent of all belligerents in modern wars fought since 1800 have employed specialized units (``blocking detachments'') authorized to kill faltering or retreating soldiers. What remains unclear is whether fratricidal coercion improves or undercuts battlefield performance. We examine this question by drawing on the personnel records of millions of Red Army soldiers in World War II. We estimate how the presence of NKVD Special Sections embedded within Soviet army divisions affected casualties and several elements of cohesion, including desertion, defection, surrender, and disappearance. We find that several indicators of soldier discipline improved as the number of NKVD officers assigned to each unit increased. Fatalities, however, worsened, suggesting that armies purchase discipline at the cost of higher casualties. We process trace the relationship between fratricidal coercion and soldier behavior by comparing matched pairs of Rifle Divisions drawn from the larger sample that fought in battles at Leningrad (1941) and Stalingrad (1942).
Jason Lyall is the inaugural James Wright Chair of Transnational Studies and Associate Professor of Government at Dartmouth College, where he also directs the Political Violence FieldLab. He is currently writing a book on how to improve humanitarian assistance in fragile and conflict settings like Afghanistan, Iraq, and Yemen. A second project investigates the relationship between inequality, racism, and intergroup relations in violent settings, including within police forces, armies, and rebel organizations. His book, Divided Armies: Inequality and Battlefield Performance in Modern War (Princeton University Press, 2020), was recently named a "Best of 2020" book by Foreign Affairs. His research has been published in the American Political Science Review, American Journal of Political Science, International Organization, Journal of Conflict Resolution, Journal of Peace Research, Journal of Politics, and World Politics, among others. He has received funding from AidData/USAID, the Air Force Office of Scientific Research, the MacArthur Foundation, the Folke Bernadotte Academy, and the United States Institute of Peace. He has conducted fieldwork in Russia and Afghanistan, where he served as the Technical Adviser for USAID's Measuring the Impact of Stabilization Initiatives (MISTI) project during 2012-15. He was named an Andrew Carnegie Fellow in 2020.