Th e profound transformations at the beginning of the century, characterized by political changes and the diversifi cation of geostrategic interests, signifi cantly infl uence the evolution of the international security system. Th e cutting-edge events in Ukraine and Syria show that it has a signifi cant change, including the trends of strategic reconfi guration of partnerships between diff erent international security organizations, depending on the interests and security objectives of the main actors, but also the major threat to security - terrorism. Under the international security system, international security organizations are the most complex forms of international government cooperation. International organizations have become an important element of the international security system, especially aft er the Second World War, when their number began to rise considerably. Globally, the number of international organizations is particularly high, so it is diffi cult to determine the specifi c role they play (between 1945 and 1949 there were about 100 such organizations, and in recent years their number is estimated to be Fourtimes higher).