The dissertation is a comparative study of the government counter terrorism policies of the liberal democratic nations of Canada, the United States, and the United Kingdom. It includes reference to the threat of terrorism as a modem phenomenon beginning in the period of the 1960s decade. While discussion centres on policies of response, attention is also given to policy measures which have developed as an outcome of those policies. The dissertation is comprised of five chapters. Chapter one is devoted to terrorism as a threat to national and international security and stability. The context describes problems associated with definition of terrorism, motivational aspects, the aims and strategies of terrorists, group infrastructure, and factors and implications of current and future importance. Chapter two is concerned with an examination of general policies of response adopted by the three subject nations. Discussion relates to characteristics of policy, the philosophy of the use of force, policy development, fundamental policies, and the translation of those policies into direct (active) and indirect (passive) measures. Chapter three provides a description of the decision-making and crisis-management machinery peculiar to Canada, the United States, and the United Kingdom in regard to counter terrorism activity. Chapter four reviews a range of resources and capabilities available to those nations for response to the threat of terrorism. Specifically included are factors of policy, experience, infrastructure, law enforcement agencies, the armed forces, legislation, and the role of the media. Chapter five summarizes general comments on strengths and weaknesses of the policies and policy measures presented in the preceding chapters. Many of the salient points are contained in the observations put forward in chapter five, but some judgements must necessarily be left to a reading of individual chapters. In conjunction, chapter two includes a brief commentary on the Cycle of Activity involving the threat of terrorism and the mechanics of governmental reaction to that threat. Acting upon the Cycle is a spectrum of other factors,' termed the Envelope of Influences, which has. a significant effect upon all the components. The Envelope is a combination of such influences as environment, history, culture, precedent, ideas, pressure groups, et al, which must be taken into consideration when assessing policy and policy measures. Judgements of policy and policy measures (taking into account the Envelope) were based upon four principal aspects of governmental performance; 1. Perceptiveness; 2. Capacity to Adapt to New Challenges; 3- Practicality; and, 4* Adherence to Legal, Democratic, and Moral Principles. The context of chapter five, as well as that of chapters two, three, and four, reflects that approach.