Black Watch at the Battle of Quatre-Bras, 1815

The Geopolitical Reading List: Divided Armies – Inequality & Battlefield Performance in Modern War

As a follow-on from our 2020 Geopolitical Reading List, in this piece we review Jason Lyall’s fascinating new piece, Divided Armies: Inequality & Battlefield Performance in Modern War.


“What a society gets in its armed services is exactly what it asks for, no
more and no less. What it asks for tends to be a reflection of what it is.
When a country looks at its fighting forces it is looking in a mirror: if the
mirror is a true one the face that it sees there will be its own.”
-General Sir John Winthrop Hackett

Divided Armies asks a critical question that has been explored by military academies, commanders and defence ministries the world over: What makes armies win on the modern battlefield?

Jason Lyall – the director of the Political Violence Field Lab and Associate Professor of Government at Dartmouth College – tackles this question in an extremely unique approach through blended numerical, sociological and political analysis to understand the impact of social inequalities on military capabilities.

In a bold approach that draws on the groundbreaking Project Mars conflict dataset of 250 conventional wars, Lyall controls for and largely sets aside state military budgets and the associated disparities in equipment quality and technology levels, and instead the focus is very much on the society fielding the military force, and the ethno-social composition of the troops within its ranks. The output is truly fascinating, asking whether societal inequalities breed poor armies, and arguing compellingly that the higher the levels of inequality in the society fielding the force, the higher the rates of desertion, treachery, coerced-fighting and even casualties.

Divided Armies dives headlong into 250 conventional conflicts since 1800 and comes out with highly impressive arguments for the strength of a unified and inclusive society. The book also stands apart from much of recent military science in that it takes a truly global view of the issue, avoiding the traps of a western-focused approach. While the book is certainly heavy-going (as any data-driven study is given to be), it is extremely valuable reading and should be considered critical for the reading lists of all key military policymakers, aspiring officers and students of military science.

I would strongly recommend this piece to a more intermediate or advanced-level of geopolitical reader, but given the laser-focus of the topic, any student of military science is likely to find valuable insight in Lyall’s work.


Encyclopedia Geopolitica was kindly provided with a review copy of “Divided Armies: Inequality & Battlefield Performance in Modern War” by Princeton University Press for this article. 

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Lewis Tallon is a former British Army Intelligence Officer with extensive experience working and living in the Middle East and North Africa region and Asia Pacific in security, geopolitical, armed conflict risk and threat intelligence roles. Lewis currently specialises in providing MENA-region geopolitical intelligence support to the technology sector, the oil & gas industry, and the financial services world.

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Cover Image Credit: Black Watch at the Battle of Quatre-Bras, 1815, William Barnes Wollen