The Soviet Union had already confirmed the orders to attack Germany in 1940

Document No.103202/06 signed Chief of Staff Kirill Meretskov on 1940, revealed that Stalin was preparing to invade Western Europe on July 1941 in a massive invasion called Operation Groza ("Operation Thunderstorm").

It is dated 18 September 1940, three months before the German "Operation Barbarossa" was signed. After Georgy Zhukov became Chief of the General Staff in February 1941, the plan was called MP 41 (Mobilisatsyonni plan 41). It can be found in the so-called "Osobaya Papka", a file which contains about 100,000 top secret documents.