I'm just now reading The Promise, Part 1 and I'm at the part where Zuko and Aang argue over the Harmony Restoration Movement. Aang believes that all Fire Nation citizens, soldiers, etc. should be expelled from the Earth Kingdom completely. Zuko feels that since some of the Fire Nation people had occupied the Earth Kingdom, especially in cities like Yu Dao, they had the right to stay.
If this issue could be compared to any issue that occurs in modern times, I would say it reminds me a bit of the illegal immigration debate we currently have in the United States. Some say that if undocumented (illegal) immigrants have been here for 25 years+, they should stay. Others argue that the 25 years+ people are just as illegal as the 1 year people.
I believe I side with Aang on this one. The Fire Nation people's ancestors had no right to occupy the Earth Kingdom in the first place, and it isn't justified just because it is 100 years later.
What do you think?