I'm positive it could be read in many ways, but in a Western country that has pretty much viewed "Asians" either as "poor rice farmers that need saving" or "Fu-Man-Chu orientalist villians" there was a pretty good chance that us anglos would wind up thinking the Fire Nation were Chineese/Japanese WWII/Cold War analogs.
I thought it was less of one nation and more of industrialization and the industrialized powers (including the us)
I'm positive it could be read in many ways, but in a Western country that has pretty much viewed "Asians" either as "poor rice farmers that need saving" or "Fu-Man-Chu orientalist villians" there was a pretty good chance that us anglos would wind up thinking the Fire Nation were Chineese/Japanese WWII/Cold War analogs.