The article has been dedicated to the issue of the eastern dimension of NATO, with a special consideration of the evolution of NATO’s policy in this regard, the extension of the organization, as well as bilateral relations with Russia, Ukraine and Georgia. In the article, the circumstances of the cooperation between NATO and those countries have been discussed, the instruments and mechanisms of such cooperation, as well as the evolution of the Euro-Atlantic policy of Ukraine and Georgia. The article also describes the consequences of the annexation of Crimea and the conflict in the eastern Ukraine, as well as their impact on NATO’s policy. Therefore the decisions made at the NATO summit in Warsaw, directed towards improving the security of the eastern flanks, and Russia’s position in this matter are also analysed.