The current research reviews the topic of the potential future borders of the European Union in great details. It uses the combined methodological approach involving the qualitative and quantitative assessment of the economic, political, geographical, and civilization factors of the EU member countries and its potential members. The analysis particularly focuses on the following potential members: Georgia, Ukraine, Switzerland, Bosnia and Herzegovina, and Turkey, analyzing them based on the mentioned factors to identify the possibility of their accession in the future. The thorough historical background of the current research, as well as the fact that its theoretical foundation lies on the official governmental documents of the EU, its official statistics, and official reports, which express the opinions of the EU legislative bodies, contribute to the credibility and precision of the research, allowing it to reach its main aim: to identify the future potential borders and members of the European Union.

La politique européenne de voisinage (PEV) est née de la volonté de développer un espace de prospérité et de stabilité aux frontières de l’Union élargie. Elle vise à renforcer la coopération politique, sécuritaire, économique et culturelle entre l’UE et ses nouveaux voisins immédiats ou proches, tout en atténuant le caractère séparatif des frontières européennes en engageant les pays voisins dans une coopération mutuellement avantageuse avec l’UE. La thèse étudie le volet oriental de la PEV qui couvre des Etats de l’Est (Ukraine, Biélorussie, Russie). Ces pays occupent aujourd’hui une place croissante dans la stratégie internationale de l’UE. L’adhésion des nouveaux pays membres de l’Europe centrale en 2004 a apporté une nouvelle fragilité, tout en créant un fort groupe de pression qui demandait un engagement direct de l’Union européenne dans les affaires concernant don voisinage immédiat. Disposant d’une parfaite connaissance de la situation économique de cette région et d’une grande expérience de coopération avec la Biélorussie, la Russie et l’Ukraine, ces pays cherchaient à orienter la politique étrangère de la Communauté vers de nouvelles voies d’actions. L’objectif de recherche concerne l’évaluation globale du rôle et de la contribution des nouveaux pays membres, et plus particulièrement de la Pologne, dans l’élaboration commune de la politique orientale de l’Union européenne dans les années 2004-2007. / The European Neighbourhood Policy (ENP) was developed in order to insure a zone of stability and prosperity on the borders of the European Union (EU). It aims at strengthening political, economic, cultural, and security cooperation between the EU and its neighbours. Its objective is to engage neighbouring States into a mutually beneficial cooperation with the EU. The present doctorate thesis focuses on the Eastern dimension of the ENP which includes Eastern States like Ukraine, Belarus and Russia. These countries have an important role to play in the EU international straetegy. New Eastern European countries adhering in 2004 brought in a new frailty yet creating a strong pressure group asking for a strong commitment of the EU in matters related to immediate neighbourhood. Those countries are thoroughly aware of the economic situation of the region and have a wide experience cooperating with Belarus, Russia and Ukraine; they sought to have an influence on the Community's foreign affairs policy by means of new paths of action. The aim of this research concerns the global evaluation of the new Members States' - and Poland's in particular - part in and the contribution to jointly elaborating the Eastern European Union's eastern policy for the years 2004-2007.