The author presents a new European security environment after the “Cold War”, including not only the challenges and threats to the international security but also the essential conditions and problems of the European security evolution at the beginning of the 21st century. He shows the dynamic and constant changes taking place within the international environment and those related to the progress of civilization. Moreover, he stresses that current policy and security measures are not capable of effective action against having to appear before the new challenges and threats. Then the problem of unity and identity in the transatlantic relationship is taken. According to the author, in complicating sphere of the international conditions the role of multilateral institutions effectiveness in the international cooperation increases. Due to the increasing importance of interdependence and internationalization, European security challenges are European-wide and even transatlantic. Addressing them requires the preservation of unity that will be possible by strengthening common identity based on shared values and common interests.