The most important part of the agreement was the secret protocol , which provided for the partition of Poland , Finland , and the Baltic States between Nazi Germany and the Soviet Union and for the Soviet annexation of Bessarabia ( then part of Romania , now Moldova ) . This protocol gave Hitler the green light for his invasion of Poland , which began on 1 September . On 5 March 1940 , Lavrentiy Beria gave Molotov , along with Anastas Mikoyan , Kliment Voroshilov and Stalin , a note ordering the execution of 25,700 Polish officers and anti-Soviets , in what has become known as the Katyn massacre
Katyn massacre
Katyn massacre
Vyacheslav Molotov