Terrorism motivated by Islamist religious ideology has been on the rise for the last forty years and has been called the fourth wave of terrorism. Generally speaking, the previous Anarchist, Nationalist, and Marxist waves arose out of some combination of geo-political events and local grievances. The current wave, however, did not seem to arise out of any analogous conditions. While there were certainly events that helped catalyze Islamist movements, these events did not seem to create the specific grievances that would lead us to expect the wave of terrorism that followed. In other words, our commonly held notions - of how changes in structural conditions lead to grievances that, in turn, give rise to terrorism - fail to explain the current Islamist wave of terrorism. Absent a better explanation of this current wave of terrorism, our understanding of it is flawed, as are the policies and actions taken to mitigate and defeat it. In The Global Spread of Islamism and the Consequences for Terrorism, Michael Freeman examines the causes of terrorism, and how potential causal factors have changed over time by looking at several key events of 1979, how these events created incentives for different actors to spread the supply of Islamism, the institutions that they created in various countries, and the terrorists coming out of these institutions. 1979 marked the emergence of revolutionary Islam as a global political force, the beginning of market revolutions in China and Britain that would radically alter the international economy, and the first stirrings of the resistance movements in Eastern Europe and Afghanistan that ultimately led to the collapse of the Soviet Union. By tracing the conflict in Syria, terrorism and sectarianism in Iraq, the war in Yemen, the nuclear and missile programs, the security apparatus in Iran, and fundamentalist operations around the world, Michael Freeman looks at the broader, and more accepted (and not necessarily violent) ideology from which many Islamic terrorists eventually arise.