I've brought up my own situation a few times in these threads. My great grandfather emigrated from Italy 100 years ago last month. He became a US citizen, renouncing his Italian citizenship in 1943, less than a year before one of his sons was killed in Normandy. In the meantime, my grandfather was born in 1920. Now, according to Italian law, because my grandfather was born before my great grandfather renounced, Italian citizenship passed to him. He never knew this, and never made a point of renouncing it. Then my mother was born and under that same law, citizenship passed to her, and from her to me. If I provide a bunch of documentation--birth certificates, marriage certificates, etc.--I can get an Italian passport. This is not the same as applying for citizenship and naturalizing as an Italian. Under their law, I already AM an Italian citizen.
So here's the question: I'm three generations native born. Am I a natural born citizen? Or does a quirk of Italian law disqualify me? By way of contrast, if my great grandfather was say, Spanish, none of this would apply. They are strictly jus soli.
Is American law subject to and subservient to foreign law?
That is a really, really good example. Thanks.