The key feature of the text is its concise, scholarly depth, and accessible format, which enable readers to gain a clear understanding of the theory that they may use in future research. Current texts on the market include redundant, lengthy presentations of theories that fail to distinguish among key theoretical contributions. Terrorism is an area of urgent global concern. The number of terrorism and homeland security-focused academic programs, think tanks, and research centers has dramatically increased over the past two decades. Many universities now offer courses on issues related to terrorism at both the undergraduate and graduate levels within the social science disciplines as well as interdisciplinary centers. Yet, there is only one text and a few book chapters on theories of terrorism. The approach that we will use in the book will make it attractive to academics, students, and policy makers who seek to develop theoretically-driven approaches to policy making. Considering the current number of programs on terrorism and homeland security within the United States alone, the growing emphasis on terrorism studies across the world, and the absence of a clear text on theories of terrorism, the demand should be quite high. This will be the only text that offers chapter-length descriptions of each stage of the radicalization process covering pressing issues in the field of terrorism.