Most of the time war is started over a country’s want for power or more land, it’s not often that a war’s main focus is that the opposing side is morally “bad”. In WW2 we often look back and see it through the Lens of the Allied forces fighting against the evil Axis powers but almost if not all of the conflict was started by the axis powers trying to obtain land, it was only later when people learned about the interment camps and horrible human rights violations that anyone really though of WW2 as a fight against evil.
Wars tend to be interpreted very differently depending on the side you ask since a lot of the time both or neither side is fully morally correct in their reasons for fighting.
Hope that helped!