Stosunki wojskowe między Rzecząpospolitą Polską a Związkiem Radzieckim w latach 1921-1939

The article presents the military relations between Poland and the Soviet Union in the years 1921-1939, from the end of the war between Poland and the Bolshevik Russia until the beginning of World War II. Its content has been divided into four subchapters, in the first of which the author analyzes the state of research on the topic in question and the state of preservation of sources in Polish and foreign archives. In the following subsections, the author presents the military relations between Poland and the USSR in three periods: in the years 1921-1926, 1926-1935 and 1935-1939. The last subsection is key to the undertaken research problem. It contains findings on the changes in the mutual military relations to the disadvantage of Poland, in connection with the rapid expansion and modernization of the Red Army and the difficulties of the Polish military intelligence in their assessment and difficulties in recognizing the reconstructed cooperation between the USSR and Germany.