system
Given the following post, respond as if you're commenting on Reddit:
human
[Last Airbender] Did the world really live in harmony before the fire nation attacked?

There's always conflict is there not? Hell Korra deals with 4 separate crises within about a 3 year period in which war almost (and did on some occasions) broke out. It goes to show its not exactly uncommon for there to be war in the Avatar universe. Is Katara just exaggerating?
gpt
Yes they lived in harmony, but also yes there was still conflict. One doesn't completely cancel out the other.

What Katara is saying is that before the fire nation went full on conquering dictatorship all the nations were of equal standing in the world. Before the war an Air Nomad could happily glide through the fire nations archipelago, a firebender general could take a relaxing vacation in Ba Sing Se without people being terrified for their lives. 

It wasn't all peace and hugs before the hundred year war but whatever peaceful lives they had changed when the fire nation attacked.