The term refers to several events, including the treatment of Czechoslovakia during the Munich Agreement and the resulting occupation by Germany, as well as the failure of France and the UK to aid Poland when the country was invaded by Germany and the Soviet Union in 1939. The same concept also refers to concessions made by the United States and the United Kingdom to the Soviet Union during the Tehran, Yalta, and Potsdam conferences and to their passive stance during the Warsaw Uprising against Nazi occupation, and post-war events, which allocated the region to the Soviet sphere of influence and created the communist Eastern Bloc.