" In some cases, however, limited violence against the dictatorship may be inevitable. Frustration and hatred of the regime may explode into violence. Or, certain groups may be unwilling to abandon violent means even though they recognize the important role of nonviolent struggle. In these cases, political defiance does not need to be abandoned. However, it will be necessary to separate the violent action as far as possible from the nonviolent action. This should be done in terms of geography, population groups, timing, and issues. Otherwise the violence could have a disastrous effect on the potentially much more powerful and successful use of political defiance. "

― Gene Sharp , From Dictatorship to Democracy