ENThis study seeks to discuss one of the major aspects (in my view) of the Eastern policies pursued by Poland as a re-emerging state after the First World War, confronted with the federation-oriented policy of Józef Piłsudski, the then-Chief of State, and the differing viewpoints of his opponents. This book explores the approaches adopted in relation to the actions taken by Poland in the Eastern territories not only by Germany, which had been on the losing side in WWI, but also by the victorious Entente powers. The collapse of Russia made them face a range of interwoven problems that their political elites had not previously contemplated, and thus lacked the necessary tools, let alone the essential knowledge, to effectively shape the new political reality. The interests of Russia, the notable absentee, and its increasingly active new rulers at the Kremlin, also played a crucial role. In this context, the actions of the newest entities on the world map and subjects of the events in question, i. e. Lithuania, Byelorussia, and Ukraine, was of lesser significance, although not negligible, either. [p. 11].