So here’s something interesting about ATLA Season One
Episode 6, The Imprisoned, has a scene where Earthbender Haru helps an old man, a citizen of the Earth Kingdom.
Later in the episode, the Earth Kingdom elder sells Haru out to the Fire Nation! It’s implied that he did this proactively to protect himself/get a reward but it’s not elaborated on. This is the main catalyst that sets off the rest of the conflict of the episode and eventually leads to the GAang saving the Earthbenders.
Now, compare only four episodes later, Episode 10: Jet.
In this one, Jet’s gang stops an old man in Fire Nation colors (colonist?), and it’s heavily implied that they were either going to beat him up or outright kill him during the encounter. Sokka breaks it off and spares the old Fire Nation man.
Later in the episode, when Sokka is trying to convince a town of both Earth Kingdom citizens and Fire Nation soldiers that they’re in danger, the old Fire Nation man vouches for him, resulting in saving the lives of everyone in that town.
Now, given some of the S1 writing (it’s not bad, but it’s much more polished in the later books) it’s possible this is only incidental. But I think there’s a solid chance this is a deliberate contrast. It especially sets up the important point that although the Fire Nation is the obvious and overwhelming aggressor and oppressor in this war, not everyone in red is evil and not everyone in green is good. This sets up for the fact that the GAang can’t save the world without saving the Fire Nation, amongst other revelations. It’s a pretty interesting comparison they did there.