Before invading Poland, Hitler reached a secret agreement with the SOVIET UNION.
The Treaty of Non-Aggression between Germany and the Union of Soviet Socialist Republics, colloquially known as the Ribbentrop-Molotov Pact, was signed between Nazi Germany and the Soviet Union by the foreign ministers of these countries, Joachim von Ribbentrop and Vyacheslav Molotov respectively. The pact was signed in Moscow on August 23, 1939, nine days before the beginning of World War II. The effects of the treaty were diminishing with the growing hostility between both nations until 1941 when the Nazi regime decided to invade the Soviet Union.