Soviet Union and Germany in 1939

I knew they were allies right up to the day Germany crossed the Soviet border. But I never realized that without the support of the latter there might have not been the WWII at all. Germany needed a powerful ally. The two countries attacked Poland together, and so it is correct to say that both Germany and the Soviet Union started the war. You can't say that in Russia to anybody. The country suffered a lot, and the propaganda demonized Germany and at the same time pictured the Red Army as heroes. That memory is untouchable. Nobody wants to hear about what happened in Poland and Finland in 1939.
I guess most of us like history being served in a certain way.