[[Cuba determines who will or will not be their citizens by the legal means of their own determination.]]
Like I told Cdbolt, I believe that it has been found that a child born to a sovereign us citizen is a us citizen unless the parent allows the child to be sent abroad for citizenship in the other parent’s country- in which case I believe the parents would have to renounce their child’s citizenship here-
I may be wrong, but I believe US citizenship status of a parent trumps the foreign parent’s citizenship in another country- until the us citizen agrees to relinquish-
That may be true under US law but there is another nation’s law that must be considered regarding the citizenship of a child born to one of their own citizens, if that nation determines that such a child is a citizen as a result of being born to one of their own. US law does not “trump” foreign law regarding internationally recognized citizenship. It may be said to do so internally, but externally is another matter.