Two key excerpts from a 2019 European Parliament resolution, 80 years after the start of WW II:
“B. whereas 80 years ago on 23 August 1939, the communist Soviet Union and Nazi Germany signed a Treaty of Non-Aggression, known as the Molotov-Ribbentrop Pact, and its secret protocols, dividing Europe and the territories of independent states between the two totalitarian regimes and grouping them into spheres of interest, which paved the way for the outbreak of the Second World War;
And:
“C. whereas, as a direct consequence of the Molotov-Ribbentrop Pact, followed by the Nazi-Soviet Boundary and Friendship Treaty of 28 September 1939, the Polish Republic was invaded first by Hitler and two weeks later by Stalin – which stripped the country of its independence and was an unprecedented tragedy for the Polish people – the communist Soviet Union started an aggressive war against Finland on 30 November 1939, and in June 1940 it occupied and annexed parts of Romania – territories that were never returned – and annexed the independent republics of Lithuania, Latvia and Estonia”.
One relevance today: Russia’s Putin is very upset about Poland.