On June 6, as the world honors the 75th anniversary of the Allied landings at Normandy on D-Day, Russia’s Ministry of Foreign Affairs took to Twitter to claim that, in fact, “the Normandy landings were not a game-changer for the outcome of WWII and the Great Patriotic War,” and asserting that the bulk of the credit for the defeat of Nazi Germany is due to the Red Army.

The Twitter posts were followed the next day by remarks from President Vladimir Putin at an economic forum in St Petersburg, where he stated he was not at all offended by his non-invitiation to the memorial events at Normandy on Thursday. “We also don’t invite everyone to every event. Why should I be invited everywhere? I have enough business of my own here,” said Putin.

The post enraged many on Twitter. Dozens of responses came in from historians and military personnel accusing the Russian government of historical revisionism. Many pointed out that in 1939, the Soviets signed a non-aggression pact with the Germans, allowing them to invade Poland, igniting the Second World War and the Holocaust.

Fred Wellman, a U.S. Army veteran, responded: “Cool. Remember when Stalin collaborated with Hitler and then you occupied Poland and murdered thousands of their soldiers?”

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The end of World War II is commemorated as a national holiday in Russia on May 5, Victory Day, with a military parade and speeches from government officials. The USSR lost around 9 million military personnel in the fight against national socialism, and over 13 and a half million civilians, by far the highest number of casualties among the Allies.

Most historians agree that though the Red Army played a crucial role in defeating Germany, the western allies and the soviet union were mutually dependant on each other.