This chapter introduces the long-term explanation of political violence. There is a strikingly strong correlation between the intensity of revolutionary terrorism from 1970 to 2000 and the development paths of the interwar period. To characterize these development paths, six variables are employed: past anarchist terrorism, democratic breakdowns, civil wars, land inequality, type of capitalism, and industrial transition (the year in which the industrial labor force exceeded that of agriculture). These variables are summarized in a latent variable thanks to factor analysis. This latent variable can be interpreted as the degree of liberalism of the development path followed by countries. The historical variables are not only significant when included with contemporary variables, but they make the contemporary ones non-significant. The statistical analysis shows that in an analysis of historical variables plus population, almost all the cross-national variation in the intensity of revolutionary terrorism can be explained. This relationship is extremely robust.