The consept of security plays a pivotal role both in international relations theory and practice. However, despite the fact that different aspects of security problematique have been thoroughly examined in a number of Russian and foreign scholarly works, the very concept itself remains surprisingly understudied. The latter fact not only hinders all attempts to assess the evolution of security studies, their current state and prospects, but also makes it difficult to formulate expedient political strategies and security programmes to counter new challenges and threats. To find the basis for a comprehensive study of the concept of security it may be appropriate to revisit the basic ontological and epistemological foundations of the most influential approaches and theories in the security studies. For this purpose the present paper examines intensive debates on the possibility, acceptability and necessity of widening the concept of security in the post-bipolar world that swept in the Western security studies in the 1990s.

The author comes to the conclusion that these debates are framed by two fundamentally different ways of conceptualizing security – traditional rationalist and postmodernist – with entirely divergent, practically mutually exclusive, assessments of the substantive status of the subject and the object of security, of the possibility acquiring of objective knowledge of international phenomena, and of the aims of security studies in general. Accordingly, the “widening debate” can be outlined on two levels. The first level of the debate encompasses works written within the framework of traditional rationalist approaches ((neo)realism, (neo) liberalism, (neo)Marxism, conventional constructivism). The second level of the debates emerged with the introduction of postmodernist, discursive methods and practices, which provided an  alternative understanding of the very basic elements of the international relations theory, its concepts and principles. This level is represented by postmodernist, poststructuralist writings on security, with the theory of securitization serving as probably the prime example of postmodernist research programme.

This version of mapping of different approaches within the security studies may serve as a starting point for further analysis of contemporary concepts of security, clarifying their content and meaning.