Divided Armies: Inequality and Battlefield Performance in Modern War

By Larry D. Miller Joint Force Quarterly 99


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Divided Armies: Inequality and Battlefield Performance in Modern War. By Jason Lyall. Princeton University Press, 2020.
Divided Armies: Inequality and Battlefield Performance in Modern War. By Jason Lyall. Princeton University Press, 2020.
Divided Armies: Inequality and Battlefield Performance in Modern War. By Jason Lyall. Princeton University Press, 2020. 528 pp. $35.00 ISBN: 978-0691192444
Photo By: Princeton University Press
VIRIN: 201113-D-BD104-049

Divided Armies: Inequality and Battlefield Performance in Modern War
By Jason Lyall
Princeton University Press, 2020
528 pp. $35.00
ISBN: 978-0691192444

Dr. Larry D. Miller is the Director and Professor of Communicative Arts at the U.S. Army War College.

Why armies win wars or suffer battlefield defeats has long piqued the curiosity and interest of military historians, war planners, and strategists alike. Theorists commonly attribute military effectiveness (or not) to force ratios, firepower, technological superiority, material/resourcing advantages, or exceptional leadership (possibly aided by surprise or dumb luck). Jason Lyall, however, advances a groundbreaking analysis for understanding who wins, who loses, and why. In the process, he suggests equality as a key element in better designing military forces positioned for battlefield success.

His argument is that political communities necessarily and invariably import existing ethnic, racial, religious, and/or societal hierarchies into military organizations—organizations that are political extensions of the state poised to inflict violence. Preexisting inequalities create friction, promote division, diminish organizational cohesion, and undercut battlefield performance to varying degrees. Military inequality, a measurable construct introduced by Lyall, is a function of identity as it relates to group membership and relational standing within the political community weighted by inclusion, discrimination, or repression. This concept includes all group members who enjoy full standing, those who are marginalized, those who suffer sanctioned discrimination, and those who experience collective repression. Lyall’s extensive, detailed, and well-crafted book effectively demonstrates the validity of his hypothesis and how high levels of military inequality negatively affects battlefield performance. Armies rife with politically sanctioned inequalities, therefore, are flawed by their very design.

The evidence Lyall presents is original and compelling. The opening chapter overviews the genesis of his thinking while detailing essential concepts, terms, and definitions. The balance of the book, eight chapters and two appendices, is organized under three major headings: “Theory and Initial Evidence,” “Historic Battlefield Evidence, and “Extensions and Conclusions.” The chapters present detailed historiography, quantitative analyses of data drawn from Project Mars, and case studies purposefully selected to challenge and assess the strength of his argument from various angles. Project Mars, the culmination of a 7-year research effort, documents direct force-on-force conflicts between 1800 and 2011. Building the Project Mars database required the support and expertise of 134 coders tracking primary documents and secondary sources across 21 languages. The goal was to construct a global military database documenting armed conflicts in the modern era. Containing 825 observations of belligerence, the database complements, and will possibly supersede, portions of the Correlates of War Project database.

Throughout the book, Lyall employs statistical analyses and historiography—a potent combination of quantitative and qualitative methods—to assess cross-national military inequality against measures of battlefield performance. Hypothesized expectations include, for example, that as the coefficient of force inequality increases, tactical and operational sophistication will decrease, battlefield fatalities will increase, defections will increase, and coercion and fratricidal violence within the force will rise.

Lyall’s detailing of a well-researched conflict in the latter 1800s is particularly illustrative and serves as a preliminary test of his hypothesis. In brief, Muhammad Ahmad (known as the Mahdi) built an inclusive and egalitarian political community from diverse tribes, clans, and ethnic groups in what is primarily present-day Sudan. He assembled an army that defeated Egyptian and Anglo-Egyptian forces during the first Mahdist war (1881–1885). Following the Mahdi’s early and unexpected death in 1885, his successor initiated sweeping changes that infused poisonous identity politics into the community. Some tribes and ethnic groups were favored, some were not, and some experienced state-sanctioned repression. In due course, the Anglo-Egyptian forces returned and claimed a resounding victory during the second Mahdist war (1896–1899). Numerous accounts for this reversal of events exist, including arguments about improved weaponry and technological advantages that favored the British. Lyall’s careful matching of covariates and contextual variables, however, along with insights from primary and secondary source material, successfully illustrates the “relationship between inequality and battlefield performance.”

Divided Armies is an inviting and challenging read, one that necessitates and rewards thoughtful investment. Readers who are unfamiliar with notions of independent variables, covariates, paired comparisons, and regression analysis may find some elements of the discussion obscure and possibly off-putting despite the author’s solid and generally successful efforts to deliver a book with minimal technical jargon. Some will also undoubtedly critique the emphasis on land-based operations in the case data; however, the conclusions are applicable across the joint force. Regardless, the book is well-written and worth the intellectual bandwidth required to parse through the meticulous research.

The joint force will find much to consider in Divided Armies as the national security enterprise adjusts to confront 21st-century challenges. Lyall’s work suggests inclusivity as a way forward, especially in uncertain times. The future of war is unknown in many respects, but absent full-on technological destruction, one can predict that the tensions between globalization and nationalism will continue, variously propelling and repelling the desirability of diversity within national and international communities. Yet Lyall has convincingly demonstrated that the most successful armies will not only be diverse, but they will also embrace diversity as strength and use that strength to repel and defeat armies unable to overcome their own inequalities. JFQ