This book offers the first systematic analysis of economic thought concerning war. It retraces debates on war from the formation of European states, the rise of Mercantilism, to Colonialism, Imperialism, the World Wars and the Cold War. Allio shows different economic perspectives from which it is possible to study war as a tool to achieve economic ends: causes, consequences, costs, funding methods, and effects on the economic status of the state and on the well-being of citizens. Examining interpretations from Smith, Hobson, Keynes, Kalecki, Stiglitz and many more, this important volume addresses the economic implications of war from the perspectives of many who bore the costs of wars in reality.