White Supremacy was a key platform of the Nazi Party, which initiated World War II. Their definition of "white" including most of Western Europe but essentially none of Eastern Europe. While Slavs and Russians were better than the Roma (aka Gypsies) or Jews in Nazi eyes, they were accorded a lesser status than Germans or other Western Europeans.

In absolute terms, more Russians died as a result of Nazi action than any other group.

This is not a matter of perspective. This is what actually happened.