A form of terrorism that is receiving increased attention is human rights abuses on the part of individual states. This study, written by specialists from several countries, attempts to define the parameters of state terrorism, analyze its causes, and identify the types of data and methods needed for policy-relevant research. It focuses on state use of acts of terror to intimidate, pacify, coerce, or destroy whole populations, groups, or classes of citizens. The problems encountered in the study of state terrorism, particularly in the areas of definition and measurement and in the difficulty of obtaining complete and reliable data, are first discussed. The political origins of state violence and the mechanisms that sustain it are traced in a theoretical analysis, and the relation of national security ideology to the imposition of terrorist measures is explored. The forms of state terrorism and repression encountered in the Third World are considered next. Other topics covered include genocide, terrorism and counterterrorism in the context of democratic society, and the international terrorist impact of superpower politics. Finally, the prospects of bringing state terrorism under the control of international law are assessed.