ok, thx for the input. It's still a *hugely* controversial topic for me, because the Nazis had their plans to conquer the "Lebensraum Osten" for a long time.
And that was also known by the Soviets. So it could have been also preparation for a pre-emptive attack on highly expansionist Germany.
Disclaimer: I don't want to defend Stalin, who was a mass-murdering imperialist. But I think almost all the interpretations of this part of 20th century history are heavily influenced by ideology. I try to get bits and pieces from different perspectives, but even with the ones that pretend to have a neutral position, it is difficult.