War of the Flea - Written before the peak of the Vietnam War, this book profiles multiple revolutions across the globe. A must-read for understanding the basics of insurrection.
Partisan Warfare - The lost lessons of World War II are subtly told within this book. While the conventional warfare aspects of the European conflict are portrayed in movies and novels ad nauseum, little mention is given to the fact that the Allies were supporting every Nazi resistance movement in Europe.
The Tipping Point - Understanding the basics of how a trend starts is essential to comprehending the epidemic-like spread of insurgent sympathy and support among the population.
Brave New War - Globalization and modernization have dramatically changed the face of modern warfare and revolution. This is the template to view any types of proliferation social networks, whether narcotic, ideological, or ad hoc munitions.
Inside the Jihad - Understand the culture and the strategy writes itself. This is probably one of the best insights into the clandestine nature of self-radicalized mujahidin living in Western societies and connected to oveseas terrorist/guerrilla movements.