"Lyall’s important work arrays data from 250 wars since 1800 to prove systematically what Washington, Grant, and Eisenhower described: that the political compact between a country and its fighting forces is a major determinant in warfare. This beautifully written book brilliantly blends quantitative and qualitative methods to show that what states choose to do about status and belonging—about political identity—before wars decisively affects their forces’ ability to persevere in combat."—Kori Schake, International Institute for Strategic Studies
"Inequality can prove dangerous for the battlefield fate of armies. Lyall, in this smart and timely book, warns us all that the divisions within a community are reflected in the divisions within the armies that represent them—with devastating costs. A critical read for policymakers and scholars alike."—General (Ret.) Stanley McChrystal
"Based on assiduous archival, autobiographical, and historiographic research along with a newly created comprehensive dataset of all conventionally fought wars since 1800, this brilliant page-turner will delight aficionados of military history and open new paths for experts seeking to uncover the correlates of warfare. Lyall’s simple but powerful thesis—ethnic discrimination among units comprising a belligerent army leads to battlefield failure—is original and compelling."—David D. Laitin, Stanford University
"In Divided Armies, Lyall’s argument about the link between military inequality and military effectiveness is smart and novel. The data gathering is extremely impressive, as is the care given to the qualitative and quantitative assessments. I highly recommend it."—Michael C. Horowitz, University of Pennsylvania
"Ambitious in scope, Divided Armies offers a new theory for an important subject: battlefield military effectiveness in conventional wars from the 1800s to the present. Marshaling an impressive array of empirical evidence to support his arguments, Lyall addresses a topic that will interest policymakers, scholars, and readers from a variety of disciplines."—Jasen J. Castillo, Texas A&M University
"A major contribution to any literature that seeks to understand military design or behavior. . . . [Lyall’s] valuable empirical work and data collection - and clear methodology - will provide numerous avenues for further research to anyone with an interest in civil-military relations and conflict.—Max Margulies, Political Science Quarterly"
"The book provides the theoretical basis for an intuitively grasped characteristic of armed forces around the world today and through history. Its argument should inform future policymaking, as well serve as a basis to re-examine past wars."---Axel Dessein, Wavell Room
"An extraordinary achievement, providing new ideas about the non-material determinants of battlefield performance, and presenting compelling quantitative and qualitative evidence. It will no doubt shape research agendas on war for many years to come."
"An inviting and challenging read, one that necessitates and rewards thoughtful investment."---Dr. Larry D. Miller, National Defense University Press
"A welcome mingling of the traditions of quantitative and qualitative political science. He sets a rigorous and imaginative methodological standard that others will struggle to match."---Lawrence D. Freedman, Foreign Affairs
"Winner of the Edgar S. Furniss Book Award, Mershon Center for International Security Studies"
"Winner of the Best Book Award, Conflict Processes Section of the American Political Science Association"
"One of Foreign Affairs' Best Books of 2020"
"2019 War on the Rocks Holiday Reading List"
"Winner of the Peter Katzenstein Book Prize, Cornell University Department of Government"
"Winner of the Lepgold Prize, Mortara Center for International Studies, Georgetown University"