On the night of 23-24 August 1939, a non-aggression pact between Germany and the Soviet Union, commonly known as the Molotov-Ribbentrop Pact, was signed in Moscow. The document was accompanied by a secret protocol settling the new division of Europe. The pact ended a period of peace and opened the way for Hitler and Stalin to invade Poland on 1 and 17 September 1939 respectively, leading to the outbreak of the Second World War.

Cooperation between Germany and the Soviet Union had taken place long before 1939. In 1922, the two states concluded a treaty in Rapallo, Italy. An agreement on military cooperation was concluded shortly afterwards. As part of it, the Germans were given the opportunity to test and improve aircraft and tanks on the territory of the Soviet Union, that is, those types of armed forces that under the terms of the 1919 Treaty of Versailles Germany was not allowed to possess. In return, they were to supply armaments and ammunition and provide support in the training of the Soviet army. In 1930, there were 120 Red Army officers in German military academies. Interestingly, their lecturers included future Third Reich Field Marshals Friedrich Paulus and Erich von Manstein. After Hitler’s rise to power in 1933, military cooperation came to an end.

In March 1939, Soviet dictator Joseph Stalin presented the Third Reich in a better light than the rest of the states at the Communist Party congress. Moscow’s next nod to Germany was the change of the head of Soviet diplomacy to Vyacheslav Molotov. At the end of July 1939, Third Reich Foreign Minister Joachim von Ribbentrop said to a Soviet diplomat: “There is enough room on the Baltic for both of us and Russian interests by no means clash with ours. As far as Poland is concerned, we are following further developments carefully and without passion”.

After these words from Ribbentrop, Stalin gave his consent to the agreement. On 23 August 1939, the German Foreign Minister arrived in Moscow. The contents of the pact and the secret protocol were quickly drafted. According to it, the two sides agreed between themselves on the future division of Central and Eastern Europe, including above all Poland. According to the agreement, the territory of the Second Polish Republic was divided between the Third Reich and the Soviet Union along the rivers Narew, Vistula and San. In addition, the Baltic states of Latvia, Estonia and Finland became the sphere of influence of the Soviet Union, which also expressed interest in part of Romania. Lithuania, on the other hand, was planned to be handed over to Germany. In 2008, the European Parliament established 23 August as the European Day of Remembrance for Victims of Totalitarian Regimes.