To be strict, it was no less than Stalin who contributed to the Polish victory in 1920. He disobeyed gen. Tuchachevski's order to come to the aid of his troops charging Warsaw. Stalin and Budienny wanted to take Lvov first. However, Lwov was successfully defended and Budienny was defeated. The same was with the rest of the Soviet invasion.==
True. But the irony is that general Tukhachevski was ethnic pole himself:). And he wasn't alone. Soveit army had many poles.
Stalin never forgot who humiliated him so much. Katyn massacre was his cowardly shameful response - shooting the back of heads of those with hands tied with a barbed wire...==
They say that Katyn massacre was the Stalin revenge for those soviet POWs died in polish camps in 1920th. Stalin was ethnic georgian so very revengeful guy.
Before that he punished Tukhachevski as they say just for what you said. The Tukhachevki' critisism of Stalin.