This book investigates the persistent legal and conceptual challenges faced by the international community in establishing a universally accepted definition of terrorism. Ben Saul, a professor of international law, utilizes a comprehensive analysis of United Nations resolutions, treaty law, and state practice to evaluate the obstacles to criminalizing political violence. The work argues that the lack of a precise definition undermines the legitimacy and effectiveness of international counter-terrorism efforts while raising significant ethical questions regarding the distinction between legitimate resistance and criminal acts.

Legal scholars and practitioners frequently cite this work as a foundational text for understanding the complexities of defining terrorism within the framework of international law. Experts note the high level of academic rigor and the thoroughness of the author's examination of treaty law and state practice.