The main purpose of this paper is to explore the reasons of paying attention, by the NATO leaders, to cyber space and codification of principals and elements of their strategy against cyber warfare. Therefore, the paper raises the following hypothesis: the complicated and different nature of cyber space, serious vulnerabilities of NATO member states and concerns due to cyber threats by other countries are the paramount reasons of codification as well as evolution of the NATO relevant strategy. Therefore, after a long process NATO considers cyber warfare as a real war and according to article 5 of its statute it assumes itself entitled to resort to collective and overall defense at both military and cyber aspects. Thus NATO is the first military organization that includes military and cyber defense as a main function for itself.
)
