So you're saying that Germany's invasion of Poland in 1939 had nothing to do with it?
The actual history is that around 1600, the Old Polish Empire was the single largest and most evil country in Europe.
It was finally defeated by all the European countries allying against them.
The Old Polish Empire was the racist Scythians and Cimmerians who retreated from the Asians like the Huns, Mongols, Turks, etc.
Vlad the Impaler is an extreme example of the racist Scythians and Cimmerians.
So there was no Poland from 1700 on, until the Treaty of Versailles recreated it after WWI.
And I do not think that was a good idea.
Poland was created out of Germany and the Austro-Hungarian Empire.
And a significant portion of the Poland that the Treaty of Versailles created, was populated by Germans.
And the Polish still are racist and fascist, so I do not think it was not a good idea to return them to power, over the Germans there.
But I have no first hand knowledge that would allow me to be sure.
One overview you can get is by watching the movie "Taras Bulba" with Yul Brenner.
It shows the conflict between the Old Polish empire and migrant Cossacks around 1600.
Of course a movie can be slanted as well.
But the western part of the Ukraine is from the failed Old Polish attempt to invade Russia.
And we do see even now, that the western old Polish part of the Ukraine is very racists and fascist.
The divide was most visible in WWII, when the western half of the Ukraine supported Hitler, while the eastern half like the Cossacks, supported Russia.
But I do not claim to be an expert on it.