Examines why countries copy the military systems of one another. It is a book on theory and history. Innovative in approach, it develops a neglected area of the most influential theory in international relations. Enriches the empirical scope of IR theory with archival research from late-nineteenth-century Latin America.

Examines why countries imitate the military systems of one another. A book of theory and history, it builds on and extends the most influential theory in international relations - neorealism. It offers an alternative account for emulation and convergence in the international system. It explains why states make certain choices in how to organize, prepare, and fight wars, and how international structures shape their choices. The work develops a neglected area of neorealism, applies it in new ways, widens its explanatory scope, and offers three rich - and uncommon - historical cases based on archival research.