The article assesses the defence policy of the North Atlantic Treaty Organization in general and peace building actions aspects in particular. Distinctive feature of article can be considered the analysis of military expenses of state members of alliance submitted by the author. A special focus is made on NATO normative legal framework formation, its aims, principles of its actions, peace building policy and interaction with the Russian Federation. It is shown that the peacekeeping activity which is carried out by the North Atlantic Treaty Organization is an important component of the general system of the purposes of defensive policy of the NATO alliance.