In Part 1
of this essay on Avatar: The Last Airbender
as a political story, I discussed attempts to resolve the crisis of a worldwide war unilaterally, from the Earth Kingdom side. In that part and Part 2
I talked about the reasons why the attempt failed, and indeed that maybe it was best that it failed--because the solution had to come from inside the Fire Nation. Until a viable alternative rulership presented itself, outside intervention might have done more harm than good. Then I said that such an alternative existed in the Fire Nation due to the history of anti-war dissent starting from Roku onwards, and that the internal movement to end the war found its focus and leadership with Prince Zuko, both Sozin's and Roku's descendant, finding his conscience and his destiny.
So all the pieces are in place, and the goal is clear: Zuko would become the new Firelord, replacing his father and vanquishing his sister. He would then end the war and bring peace. His uncle and his Order of the White Lotus cohorts would retake the city of Ba Sing Se, something crucial to stabilizing Zuko's rule. Dissidents to the new Firelord holed up in the world's greatest fortress would be a headache and a nightmare for Zuko, and risked splitting his nation apart. And most crucially, the Avatar Aang would neutralize the current Firelord Ozai.
( Reasons I Love Avatar 4, Part 3 (in which we ponder kinslaying for fun and profit) )