Discussion of the secret protocols — which open up the issue of the Soviet invasion and occupation of Poland, just days after Germany's invasion from the west — are a taboo topic.
Russia has largely adopted the Soviet narrative: World War II began not with the widely held start date of September 1, 1939, when Nazi forces attacked Poland, but in 1941, when Hitler unleashed his forces on the Soviet Union.
“There's not much to be gained for Moscow in talking about 1939. Any focus on the pact contradicts the myth of the ‘Great Patriotic War’, which portrays the U.S.S.R. as a victim and lets the war begin in 1941,” explained Jan Claas Behrends, a historian at the Center for Contemporary History in Potsdam, near Berlin. “If you put the spotlight on 1939 it deconstructs this essential narrative.”
Glorifying elements of the Soviet past and blurring the lines over Stalin's brutal legacy, critics say, has become a political tool for Putin, who has exploited nationalism to prop up his rule, now entering its third decade.
Efforts to whitewash Stalin's crimes have apparently also influenced Russians’ views of the dictator, who was responsible for killing millions of Soviet citizens: a recent survey showed a record number felt he played a positive role in the country's history.
https://www.rferl.org/a/molotov-ribbentrop-what-do-russians-know-of-key-wwii-pact/30123950.html
Moscow denied the existence of the secret protocol until 1989, when Mikhail Gorbachev condemned it. But Vladimir Putin has gone back to defending the pact with Hitler. While he criticised it as ‘immoral’ when visiting Poland in 2009, more recently he’s asked ‘what’s bad about it?’. At the same time Moscow furiously denies, against all evidence, that there was ever a Soviet-Nazi alliance.
The enthusiasm of Soviet support for its Nazi ally undermines claims that Stalin concluded his pact with Hitler reluctantly. After the German attack, Moscow initiated military intelligence cooperation with Berlin. And when sixteen days later the Soviets invaded eastern Poland, the two sides agreed to coordinate in the crushing of Polish resistance. In the Soviets’ case, this included deporting up to 1.5 million Poles and murdering about 65,000 military, ‘class enemies’ and ‘counter-revolutionaries’ – including 22,000 in the infamous Katyn Massacre. Joint Soviet-German victory parades were held in Lviv and Brest-Litovsk. Stalin and Hitler exchanged warm Christmas greetings.
After the Nazi-Soviet invasion, Molotov told the Supreme Soviet ‘one swift blow to Poland, first by the German army and then by the Red Army, and nothing was left of this ugly offspring of the Versailles Treaty.’ There followed Stalin’s attack on Finland, and the invasions of the Baltic states and northern areas of Romania.
In 1940, Molotov underlined to Hitler that Russian supplies had ‘not been without influence upon the great German victories’.
https://www.spectator.com.au/2019/08/molotovs-poisonous-cocktail/
Russians are thoroughly convinced that they and they alone not only fought WW2 on largely on their own but they also won the entire war themselves.