A future history idea

A sudden collapse of American military power leaves American forces in Afghanistan and surrounding regions stranded. They can't fight their way to a friendly country and seek passage home, like in Xenophon's Anabasis, so they seize control of their regions and create what future scholars will call the Americo-Bactrian state.

So, what does that imply about a character descended from those Americans, several generations removed, who manages to get to an advanced science-fictional civilization (I would guess predominantly Chinese) and have adventures in Future World?