Alright, so Ozai was going to burn down the Earth Kingdom, right? But what did he think, the Water Tribes wrere just gonna go,"I don't want to play anymore" and give up? If he killed Aang wouldn't the next Avatar be born into the Water Tribe? Did he think that all the Earth kingdomers were in the Earth Kingdom and not in the Water Tribe or the Northern Air Temple? If anything by the end of the day he wouldn't be able to completely destroy the Earth Kingdom so it would just make them madder and start attacking more fiercely. The Water Tribes are not like the Air Nomads, their Avatar would murder him, so how did he expect to win? I mean there are HUGE flaws in his plan.