as requested by voidEnthusiast:
It was the middle of the night when Aang had a brilliant idea. After four days of sleeplessness, he'd come up with the solution. He had to speak to Fire Lord Iroh, who'd been agonizing over what to do with the former colonies since he'd taken office. So far, during the fascist hours the day, he'd been sending in troops to keep things under control, and during the anarchist times, he withdrew them. It was a compromise that upset everyone, and besides, Aang thought "anarcho-fascism" better described whatever the hell Ozai was up to these days with his homo-ethno-commune than it did literally being fascist half the time, and anarchist the other half.
But Aang had formulated a better plan: independence. But not just any independence. It would be a nationless city, populated by people of any and all cultures and ethnicities. A place that symbolized the meaninglessness of the divisions between nations and ideologies, governed by the democratic will of the people. A place called Republic City.
Ah, fuck, was that a little too far left? No, it didn't have to be. There would be police there. He could even get Toph to be the chief, even though that made no sense because she loved crime almost as much as she loved telling everyone that she was the greatest earthbender ever.
"I don't know about this, Aang," a voice said from the corner of his room.
Aang jumped, startled to see Momo perched on a chair and staring at him. "Was that you?" he whispered.
"Think about all the technological advancement that would occur if you were to build such a city," Momo said. His mouth did not move, but the voice unmistakably came from him. "The process of industrialization would destroy the natural environment."
Aang nodded slowly, an understanding dawning over him.
"Don't you think that factories such as the one you destroyed in the Fire Nation are bastions of greed and evil? Don't you think that man should halt his subjugations of nature, and rather live peacefully alongside it?"
Aang nodded faster now. Momo was right. Settling a big city would do irreparable damage to the environment.
"Don't you think that even agriculture, with how it diverts the natural courses of water and destroys the soil of the land that is farmed, was a mistake?"
"All right, now you're losing me," Aang said, rubbing his eyes to keep himself awake.
"Reject humanity, return to lemur-monke!" Momo stopped talking, his vocalizations reverting to his typical chittering.
Aang chittered along. "Reject humanity, return to lemur-monke!" He fell into a deep sleep, and when he woke, the idea of Republic City was gone.