What had the Nazis, Japanese, and other Axis nations done that justified fighting a world war?

Well the Nazis (mostly Hitler) wanted control of the whole world. And basically started blowing up other countries so England, France and a bunch of other countries started fighting back. Now the USA didn't want to join the war, but the Japanese came and blew up pearl harbour. They got real mad and retaliated. In war everyone obviously thinks there in the right but people will go to extreme lengths to do what they think is right in their eyes