But could the USA in "Future's End" have been under Augment control until recently?
As I said, that was probably an alternate past anyway. But I think it likely that the US avoided being directly affected by the Eugenics Wars, which seemed to be mostly waged elsewhere in the world. If the Khan
comic implies otherwise, I'd consider that an error, or at least something that would need to be justified.
Interestingly, Star Trek: Federation
states that North, Central and South America were unified into the American Empire at the onset of the Eugenics Wars.