EN
This article is attempt of brief characterization the Collective Security system in the theory and practice the international relations between World Wars. The paper presents four questions: l) reception of the Collective Security system of the League of Nations, 2) attempts the strengthening Collective Security system in the international scale, 3) regional conception of the Collective Security, 4) collapse of the Collective Security system. The principles of the Collective Security in the Covenant of the League of Nations were the novelty in the theory and practice international relations after the First World War. These principles were the compromise between American-British and French conception of the peaceful international relations in the post-war World, They have based on the idealistic conception about solidary action all the countries - members of the League of Nations - for defense the state being in danger of aggression regardless of their individual national affaires. From the very beginning governments and public opinion in many countries were very skeptical about the ability the League of Nations to preserve the international security and peace. As time goes on this skepticism was deeper and deeper because of fiasco to employ the Collective Security system in practice. The attempts to organize the Collective Security in the regional form were also deceptive. Towards the end of thirties the League of Nations was completely powerless to preserve international security and peace.