This book began with a puzzle. How do the weak win wars? Through a combination of statistical tests and the tracing of causal logic through historical case studies, I have shown that weak actors – in this case mainly states – win wars against much stronger adversaries when they are able to adopt and maintain an ideal counterstrategy. Strategy, in other words, can multiply or divide applied power.

Strong actors come to a fight with a complex combination of interests, forces, doctrine, military technology, and political objectives, but because armed forces are thought to be versatile in their employment, and because strong actors are only relatively, not absolutely, strong, strong actors do have choices in the strategies they use. Similarly, weak actors often face constraints in their choice of strategies, but strategy is never endogenous.