The author proceeds from the implication that problems of national security, in one way or another, concern the prospects of the development and also of survival of states. Three aspects of national security (NS) are considered in the article: (1) development of the concept of NS, as it is presented in official documents; (2) the principal threats for NS and its priorities, as viewed, ranked and, accordingly, realized by the state in its policy; (3) the required mechanism designed to ensure NS. The published part of the article contains analysis of documents.