During talks with China’s Xi Jinping on the eve of Victory Day, Vladimir Putin once again underscored the scale of Soviet losses in World War II. “The Soviet Union gave 27 million lives,” he said. “It laid them at the altar of the fatherland and the altar of victory.” Though this is the standard estimate used by Russian officials, the number 27 million often comes up in academic works, too. To this day, the question of the “cost of war” remains extremely painful, politically charged, and quite confusing from a scientific standpoint. That said, even a crash course in the principles on which this estimate is based can give you a much deeper understanding of what defeating Nazi Germany cost the people of the USSR. Meduza breaks down the origins of the oft-cited Soviet death toll of 27 million people.