Molotov was the principal Soviet signatory of the Nazi – Soviet non-aggression pact of 1939 ( also known as the Molotov – Ribbentrop Pact ) , whose most important provisions were added in the form of a secret protocol that stipulated an invasion of Poland and partition of its territory between Nazi Germany and the Soviet Union . He was aware of the Katyn massacre committed by the Soviet authorities during this period
Katyn massacre
Katyn massacre
Vyacheslav Molotov