Supply Lines explores the crucial role of military logistics in shaping the outcomes of wars throughout history. It argues that logistical capabilities, often overlooked in favor of battlefield tactics, are frequently the determining factor in military success. From ancient armies dependent on foraging to modern forces with intricate supply chains, the book reveals how the flow of resources impacts military campaigns. For example, a brilliant tactical plan is useless if an army lacks timely access to food, arms, and supplies.

The book begins by establishing the core principles of military logistics, such as procurement, transportation, storage, and distribution. It progresses thematically by analyzing logistical challenges across different historical periods and geographical contexts, and presenting detailed case studies of military campaigns where supply lines played a decisive role. Military logistics are examined through various lenses, revealing how economic resources and political decisions influence military outcomes, providing a comprehensive analysis of warfare's underlying dynamics.