‘split allegiance at birth’ ... no interpersonal relationship between the child and the citizens of the countries is required. just the familial relationship
otherwise the term ‘natural born citizen’ would not apply
as for your example, those kids if born in the local German hospital would be US and German citizens, and that choice results in them not being natural born citizens. the point wasn’t that the kids ate chicken... but had a relationship with the other country that would open the doors for favorability... or a split allegiance.
which is the whole point
American kids are born in German hospitals, although maybe Landstuhl has a maternity ward. I don’t think so, although I’m not sure.
But, you think our kids living in American housing areas, speaking English, playing football and baseball, speaking little German beyond “Guten Tag”, watching American TV via AFN, and eating at Burger King will breed some kind of sinister alliance against America with secret allegiance to Germany.
That’s more than a little odd.