How is the 9 Years War important?
The Nine Years War is important in the book because it essentially made the whole society possible, in a way.
The war was really terrible. In it, chemical and biological weapons were used a lot so many many people died. Because of the devastation that the war caused, there was a terrible economic crisis after the war.
Because of the war and the crisis, the people in charge realized they had to make drastic changes. They tried to force people to change, but that didn't work. So instead they started doing things like closing museums and not allowing literature -- the kinds of things that could make people stop thinking so much.
So, the problems caused by the war led the leaders to set up their "brave new world" to solve those problems and prevent them from happening again.