As far as I know, the Germans and the Russians attacked Poland TOGETHER. In fact, Stalin even sent a warm greeting to Hitler when he took Paris. The fact that the Russians sided with the Allies was only because the Germans attacked Russia.
That Churchill was not impressed, I can understand.
I suppose that when Putin laments Russia's grievances, he forgets them. Just as he forgets that the Allies did not build the wall in Berlin. NATO's expansion to the east may also be due to the desire of countries that are willing to join and perhaps not by accident.
If Putin could see Russia through other people's eyes, he would realise that something is wrong. Not with the people, but with their leaders, who somehow never seem to be freely elected. Those who could, either die or survive, but end up in prison. I know it is difficult to leap from the Middle Ages, but the fact is that Russia is a great power today, thanks to Hitler.
The attack on Ukraine is about someone not being able to bear to see a pattern that the Russians see as a realistic alternative to what they just can't break out of. With a leader who could emerge at any time even among the Russians. If he survives, of course.