My sister's grandfather was a Nazi soldier. He became a PoW, ending up a Canadian. Eventually married someone who had had to flee Germany. He didn't need to be shot, he'd been a kid put to serve his country
Was he really a Nazi? He could be a German soldier in World War Two without being a Nazi, just as a Russian could have fought in WW2 against the Germans without being a Communist.
Indeed. But that goes to show that Americans weren't "shooting at Nazis" in WW2. They were shooting at German soldiers, because that's what you do in a war.
Read some Vonnegut