I had a US friend, now gone, who, while in school in Germany, argued with the Hitler Youth guy who came round to talk to them about how good it was going to be. After the debate, the school principle told him to get away as fast as he could, as they would be looking for him. He moved to France then when that was over-run, Britain. He wanted to help, so, while still a German national, joined the British Army. When it became apparent he would be given unimportant duties as they didn't trust people like him, he joined the special forces and managed to get some action. Changed his obviously Jewish name to Bentley as, while likely to be executed anyway if captured, he might get better treatment.
War over, he emmigrated to the US and started a sucessful engineering company, married a very waspy lady who bred race horses.
Further down the line, after the wall went down, he had to go back and deal with the several properties that had been confiscated from his family . Virtually all of whom died in camps. We talked about it and it very tricky for him to go back, but he felt he had to do it for the few remaining members of his family who were not so well off as he.
I have rarely met such an ethical and entertaining person and miss him.