While it's stupid to contest the legitimacy of Poland, the guy did have some points that can be understood though. Poland is a tricky territory as such... German, not German, German again.. etc...... That dates way back. Starts much earlier than the 1600s.. If you will, the territory known as Poland is a clusterfuck since around the yr 1000 and continued to be that for the next 1000 yrs.
It is - if you will - an artificially dedicated zone, a country as such. And it certainly should remain that for peace and peace sake. But the point regarding the ethnic mixture is quite true... For 1000 yrs a melting pot of German and Russian heritage/influence. That doesn't go away in some 50 yrs.
Most Poles have it de facto very easy to be granted special treatment/naturalization in Germany.
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Can I have $20,00 of that stuff you were smoking?
The US traded with the UK, that much is true... But firstly rather slow, and secondly they also traded with the Nazis. And the US did not enter the war by own choice. It was dragged into it when Hitler declared war on the US. Had he not done that, it's to be questioned whether the US would have ever taken part at all, other than defending itself from future stealth attacks by the Japanese, on random targets.
In the fact of the matter.. The USA was that slow and behind the curve, that the UK would have been by the time the US showed up long defeated. For all what was needed was for the Nazis to continue their raids on the Brits. They've ran awfully low on resources, and it was but a matter of time, when they couldn't fight back anymore. Hitler just had other plans, and found it more important to open other front lines instead. Which lead to the ultimate defeat.