TNG sort of mixed up the Klingons and Romulans I think. In ""Balance of Terror" the Romulan Commander tells Kirk they are creatures of duty. Somehow, that gets assigned to the Klingons instead in TNG, leaving the Romulans floundering for a contemporary parallel. The Chinese connection surprises me, as I don't believe I ever heard it assigned to them until recently.
Borg - Americans, consuming everything through homogenization of cultures.