Civil resistance, especially in the form of massive peaceful demonstrations, was at the heart of the Arab Spring-the chain of events in the Middle East and North Africa that erupted in December 2010. It won some notable victories: popular movements helped to bring about the fall of authoritarian governments in Tunisia, Egypt, Libya and Yemen. Yet these apparent triumphs of non-violent action were followed by disasters--wars in Syria, anarchy in Libya and Yemen, reversion to authoritarian rule in Egypt, and counter-revolution backed by external intervention in Bahrain. Looming over these...