Lieber and Clausewitz: The Understanding of Modern War and the Theoretical Origins of General Orders No. 100

In recent years, the influence of the European intellectual tradition and Carl von Clausewitz's 1830s treatise On War over Francis Lieber's theories of war, particularly those expressed in General Orders No. 100, have become the source of much study. This article argues that while Lieber internalized Clausewitz's notion of war's political nature, Lieber's ideas were profoundly influenced by his time in the United States and the American Civil War itself. Clausewitz, living in a monarchical state without functioning democratic institutions, had not fully explored the interplay between war, nations, and democratic rule. Lieber's experience a generation later in the United States, where the soldiers were also citizens and the people played a direct role in the political processes, allowed him to better grasp modern war's complexities. Therefore, by transplanting and adopting Clausewitz's ideas to the American realities, Lieber created the template for waging war in the age of democratic nations.