The transformations of the political relations in Europe at the dawn of the 21st century resulted in deep changes in the concepts of security and redefining the existing systems for collective defense in Europe. NATO becoming the security and defense framework of Europe had to deeply reconsider its raison d'etre and to enlarge. In this connection the Republic of Bulgaria deeply reconsidered its political and strategic position in this new environment, started profound reforms in its security institutions and continues to consolidate the democratic statecraft. This thesis analyzes the process of NATO enlargement and advocates the possibilities of membership for Bulgaria at the next 2002 NATO summit. Bulgaria needs a quick entrance, not only for its strategic geopolitical position in Southeastern Europe, but for its efforts to participate in the building of a united Europe and to support the alliance as a reliable partner, committed to contribute and to preserve the peace and stability in the region and Europe and to promote democratic values. The membership will strengthen the process of European integration and create a better climate for economic growth and prosperity in Europe.