Inversely, because Aang was too scared to be the Avatar and got stuck in an iceberg, there was the Hundred Year War as a result.
The last air nomad Avatar in the cycle before Aang, Yangchen is often thought of as one of the greatest avatars of all time.
She’s actually kind of the opposite of Aang, in that because of her hard work and effort, there were no wars for an entire generation after her death.
In fact, she was so great, and the time of prosperity was so peaceful, that a lot of people think her successor, Kuruk (more on him in a second) had it too easy and ended up getting himself killed in the process. Bummer.