Vladimir Putin had repeated the old Soviet adage that Poland was partially responsible for initiating WWII by scheming together with Nazi Germany. In addressing Russian military leaders, the State Duma, the press corps, the SRU summit and the organizing committee of Russia's celebration of Victory Day's 75th anniversary, Putin has matched his official agenda with duly customized history.
The Russian ambassador to Poland was summoned to the Polish Ministry of Foreign Affairs to receive Poland's protest to the lies. The ambassador was told “that the Stalinist historical narrative is being constantly and aggressively implemented in the Russian historical consciousness. These totalitarian claims are contradictory to the international obligations of Russia, and are a mockery of millions of victims of the Stalinist regime, which partly include the Russian people as well”.
As a result of the Nazi-Soviet Communist Molotov-Ribbentrop Pact and the joint invasion of Poland, the country lost nearly six people people.
It's just not due to a casual whim of Russia's leadership that insists on a fictional narrative of embarrassing periods of its history. Revisionist history, Russian style, is the law. Comparing the crimes of Nazi Germany to those of the Soviet Union is forbidden, One can be arrested and convicted for “spreading intentionally false information about the Soviet Union's activities during World War II”. It's anathema for anybody to admit any collaboration with the Third Reich.
Russian authorities handle digressions from the official 'truth' fairly harshly. A Russian blogger in 2016 was prosecuted in court and found guilty of “rehabilitating Nazism” and fined 200,000 rubles for violating a 2014 law that criminalizing anything that “desecrates symbols of Russia's military history”. The blogger had shared an item on social media stating that the Soviet Union had invaded Poland in collaboration with Nazi Germany in 1941. The court insisted that the blogger had knowingly spread false information. The Russian Supreme Court upheld the decision. (Pikemalt Eesti Elu 10.01.2020 paber-ja PDF/digilehes)