Here, terror is described as “the systematic use of fear and in revolutionary circumstances to aid the establishment of a new government.” The chapter traces the modern use of the concept of terror in revolutionary circumstances beginning with the French Revolution of 1789 and continuing with examples in Communist Eastern Europe and throughout the world. The author’s argument is that the factor most conducive to the use of terror by the political opposition is its use by government, and that, if terror is to be avoided, repressive measures on the part of government must be eliminated.