Terrorism and organised political violence are a risk for individual and collective security and thus menace the very essence of every state, especially when they occur within a democratic regime. In order to minimise security risks, public authorities must avoid limiting or suppressing individuals' basic rights and democratic pluralism, which are safeguarded by constitutional and international norms. The text provides an updated overview of democratic constitutional systems in Western countries, their legislative measures in times of emergency, and the institutional arrangements set up to guarantee the non-violation of fundamental principles. Observed cases include: the British system, distinguished by strong executive powers, weak judicial control, parliamentary supremacy and lack of binding constitutional rules; the United States system, featuring limited constitutional exemptions, ample presidential and congressional powers, a wavering status of the Supreme Court's control function; the French system, with unlimited, exceptional presidential powers, weak parliamentary checks; the most widespread system, in which the constitution itself allows for exemptions and suspensions of constitutional norms in exceptional circumstances. The survey also examines other systems (Spain, Germany, Canada, Italy).

Paolo Bonetti teaches Constitutional Law, Institutions of Public Law, Regional Law, and Law of Foreigners at the University of Milan-Bicocca.