TINA ROSENBERG – Several years ago, before their protest movement was co-opted by violence, a group of young Syrians looking for a way to topple President Bashar al-Assad traveled to an isolated beach resort outside Syria to take a weeklong class in revolution. The teachers were Srdja Popovic and Slobodan Djinovic — leaders of Otpor, a student movement in Serbia that had been instrumental in the overthrow of Slobodan Milosevic in 2000. After then helping the successful democracy movements in Georgia and Ukraine, the two founded the Center for Applied Nonviolent Action and Strategies (Canvas), and have traveled the world, training democracy activists from 46 countries in Otpor’s methods. These two Serbs start with the concepts of the American academic Gene Sharp, the Clausewitz of the nonviolent movement. But they have refined and added to those ideas. In a new book, “Blueprint for Revolution,†Popovic recounts Canvas’s strategies and how people use them.