Description: At present, terrorist organizations, using minimal forces and means, can achieve significant political (ideological) goals and have a significant influence on the formation of social consciousness. Modern terrorism, as an instrument for achieving political goals, represents a multi-vector threat to any modern society and does not have state boundaries. The article analyzes the impact of terrorism on the development of the security system of European countries on the basis of statistical data. It is shown that the conduct of new terrorist acts in Europe can seriously hampers the launched fight against terrorism and reduce its effectiveness. To a large extent, it applies to countries where the emergence of terrorist organizations is still in progress and the position of the so-called Islamic State is not strong enough. Taking into account social contexts (Europeans' desire for security primarily on their own territory), there may not be a common political will and consent of European governments to engage in antiterrorist operations outside their countries. The necessity of further improvement of their security system, strengthening of special organizations, coordination of actions of the police, various services and public organizations in combating and preventing terrorism is substantiated.
Keywords: terrorism, security, European countries, so-called Islamic State