I would start by making a clear disclaimer that to my eye, both Nazism and Stalinism were genocidal regimes and historical tragedies, never to be repeated. There is however an ongoing, ideologically driven myth, according to which Stalin would have killed many more people than Hitler. Although both regimes have perpetrated genocides, it is important to be rigorous in the quantitative and qualitative aspects of these human catastrophes. The Nazi Holocaust figures have been known since the end of World War II, but the figures of the Stalinist genocide were only known in the late 1990s, when access to the archives of the Soviet Union and Eastern Europe was obtained.
A few years after the Second World War ended, the cold war started because the former allies USA and USSR had now divided Germany and Europe between the USSR and NATO. They became rivals for world domination. We all know the rest: for the Western world, the USSR became the new enemy. It was this that during the cold war perpetuated the myth that Stalinism would have killed many more people than Nazism. For 50 years it was only possible to speculate and in fact much was speculated about the real numbers of the Stalinist genocide. But then, the myth fell along with the Berlin Wall.
It is now known with considerable certainty that the Nazi Holocaust killed 12 million innocent civilians (not counting the deaths of combatants). Hitler came to power with the obsession of eliminating Jews from Europe. The Nazis were largely responsible for the happening of World War II and they mass murdered civilians for purely racist and ethnic cleansing reasons. When Germany invaded the Soviet Union, for example, it is on record that the strategy was to starve 30 million civilians and shoot down, and many more were to be shot down, deported or enslaved. They never managed to do so due to the humiliating defeat they endured in the battle of Stalingrad, which was the turning point of the war, against the Nazis … But this shows clear and accurately the policies and motivations of Nazism.
On the part of Stalinism, there were some mass murders for ethnic cleansing, but the majority were for political reasons. Another very important difference is that the Nazis killed 12 million civilians in just 7 years (1938-1945) while Stalinism killed 9 million over 26 years (1927-1953). Even if we consider all the time that Hitler was in power (1933-1945), it would only be 12 years against Stalin’s 26. This means that Nazism killed an average of 1.7 million civilians a year, while Stalinism killed an average of 346 thousand a year. Is that a small number? Is that ok, then?.. Of course not! But arithmetically speaking, if Nazism would have lasted as long as Stalinism did, an estimated 44 million civilians would have died, against 9 million for Stalin.
If we talk about the genocide of prisoners of war, the numbers are also very different. The Nazis killed 3 million Soviets in concentration camps or shootings. The Soviets killed 363,000 German soldiers in captivity. But I’d say the difference in civillian deaths numbers suffices to illustrate the point. Stalinism was a genocidal regime all right… But still can’t match the brutality and lethality of the Nazi Holocaust.