This chapter presents first the historical context under which revolutionary terrorism emerged and then summarizes the general argument of the book. Regarding the historical context, the 1950s and 1960s were years of economic convergence, with developing countries catching up with those that were more advanced. Despite this economic convergence, the countries responded very differently to the shock of the radical protests of the late 1960s. In some countries lethal violence emerged, in some others it did not. It is argued that this variation matches the variation between liberal and non-liberal developments in the interwar years. The reasons why the relevant comparison is with the interwar period are analyzed and discussed.