The most visible face of terrorism—which is embedded in the conflicts in Afghanistan, Pakistan, and the border region between the two countries—could mask an even bigger danger. In the world of counterterrorism, which includes the quiet work of intelligence gathering at home, abroad, in prisons, in mosques, and in Internet chat rooms, Western analysts are working hard to understand one of the most frightening threats, that of nuclear terrorism.In his appraisal of this menace, Todd M. Masse explores the likelihood of an attack by examining the two major schools of thought on the subject. The conventionalists, on the one hand, tend to view the possibility of a nuclear terrorist attack as highly likely over the next five to ten years. Skeptics, on the other hand, recognize the grave consequences of a terrorist nuclear detonation but tend to discount the potential of terrorists using a nuclear fission device in the United States. Upon reviewing the terrorists’ unsuccessful history with WMD, the skeptics believe that those terrorist groups wanting to create widespread panic will revert to triedand- true “conventional” attacks, which can still inflict mass casualties.Masse provides a much-needed objective assessment of the nuclear terrorist threat and suggests a range of policy options to address the danger. National security analysts and policymakers, military personnel, and graduate students in international relations and political science will find his work compelling.