Modern terror began in the late 1870s; its distinctive features are its global character, use of explosives, and emergence and recession in the form of waves. We have experienced four waves, the “Anarchist”, “Anti-Colonial”, “New Left” and “Religious”. Each wave contains a large number of independent groups, special purposes, distinctive tactics, and a distinctive geography and has a different impact on the international state system. The overwhelming number of groups in a wave has much shorter lives than a wave does, but if a group does survive the wave it was originally associated with, it absorbs some of the features in the next wave. The first three waves lasted around 40 years or a generation by Biblical standards. If the “Religious Wave” which began in 1979 follows the course of its predecessors it should basically disappear by the 2020’s decade. If history repeats itself, a fifth one will emerge. Lunch will be provided – please RSVP to beb38@pitt.edu