Ribbentrop, Stalin, Molotov in the Kremlin after the signing of the sadly notorious Pact, August 1939 70 years ago, on September 17, 1939, a few weeks after the signing of the Molotov-Ribbentrop Pact , the division of the spheres of influence in Europe, the USSR introduced its troops into Western Belarus and Western Ukraine, which was then part of Poland. Official communist propaganda called this campaign of the Red Army "liberating", "golden September".