This article offers theoretical guidelines for the current national security concept research focused on realism and its critics –liberalism and critical theory. Due to the usual understanding of the national security on a military basis with respect to the international political situation, an axiological discussion is required to analyze the wide range of the different aspects of this matter. If not considered, both academic and political activities will be deeply darkened, particularly in those countries where the military doctrine spirit has been hegemonic. In this regard, the first part of this paper explores the premises of the realistic school and their view on the national security model. The second part examines the liberal approach and, in particular, its proposed change of level of the national realism analysis. The third part explores the Critical Security Studies and the relation they keep with the critical theory with the purpose to outline its epistemic criticism to the realism as a rationalistic theory.