The popular front policy crumbled with the signing of the Molotov-Ribbentrop pact on 23 August 1939. Despite being confused about the pact, Larsen defended Stalin's decision. The German invasion of Poland on 1 September and Stalin's invasion of Poland on 17 September and the following partition of Poland between Hitler and Stalin caused more confusion in the communist movement, as the former image of the Soviet Union as a ”bulwark against fascism” now fell.