Faced with the growing threats of terrorism and international organised crime, European societies are feeling an increasing need for both domestic and external security. Government action to combat these threats must be lawful - and also legitimate - and be conducted with due respect for human rights, democracy and the rule of law, which are fundamental Council of Europe principles. The question arises as to who is going to exercise democratic oversight in this area. What are the roles of parliaments, the executive, the judiciary and civil society? Do supervisory bodies exist at supranational level? This book presents the various players and their duties in the security field and confirms the need to strike a balance between a democratic conception of fundamental freedoms and security safeguards, on the basis of reports by the Council of Europe Parliamentary Assembly and the European Commission for Democracy through Law.