The Soviet Union was in fact the most diverse nation by ethnicity. Look it up in the internet, doesn’t matter where. Russia today is still one of the most diverse nations of the world.
What's so great about diversity?
Look what it did to the American Indian.........
And Stalin did a pretty good job of trying to eliminate some of those ethnic groups -- Ukrainians, Fins, Koreans, AND Jews.
Thanks to the steady declassification of incriminating documents, however, it is now common knowledge that, through forced collectivization, show trials, ethnic purges, and costly diplomatic and military ineptitude, he was responsible for millions of deaths. We also know that at the time he died, Stalin was planning a new Terror, one that would have essentially picked up where Hitler left off in totalitarianism's campaign to destroy the Jews. Yet history has been slow to confront the reality of who Stalin was and the havoc he wrought on Russia. Over the years, a number of Atlantic contributors have commented on this slow but steady process of reevaluating Stalin and coming to terms with his legacy.
Source: http://www.theatlantic.com/doc/prem/200407u/stalin
More on Soviet ethnic purges here: http://www.socialaffairsunit.org.uk/blog/archives/001190.php
Left-right is a useless measure it comes to completely totalitarian regimes such as Stalins Soviet Union or Hitler's Germany, they lose all meaning because those regimes were about imposing their will over all. Who they decide to kill is simply a tactical decision designed to solidify their power base. The philosophical foundation is rule through terror.
Cause if it's "in" the internet, you know it's true!
If you define ethnicity as ancestry, the United States had the Soviet Union beat several times over, and had ancestries from more than just Europe, Central Asia, and North Asia.