Taking as a starting point the widely accepted view that states confronted with terrorism must find a proper equilibrium between their respective obligations of preserving fundamental rights and fighting terrorism effectively, this book seeks to demonstrate how the design and enforcement of a human rights instrument may influence the result of that exercise. An attempt is made to answer the question how a legal order's approach to the limitation of rights may shape decision-making trade-offs between the demands of liberty and the need to guarantee individual and collective security. In doing so, special attention is given to the difference between the adjudicative methods of balancing and categorisation. The book challenges the conventional wisdom that individual rights, in times of crisis, are better served by the application of categorical rather than flexible models of limitation. In addition, the work considers the impact of a variety of other factors, including the discrepancies in enforcing an international convention as opposed to a national constitution and the use of emergency provisions permitting derogations from human rights obligations in time of war or a public emergency. The research questions are addressed through a comparative study of the terrorism-related restrictions on five fundamental rights protected under the European Convention on Human Rights and the United States Constitution: the right to freedom of expression, the right to freedom of association, the right to personal liberty, the right to privacy, and the right to a fair trial. The book offers both a theoretical account of the paradoxical relationship between terrorism and human rights and a comprehensive comparative survey of the major decisions of the highest courts on both sides of the Atlantic.