Personally, I think the Axis powers lost any right to claim they were justified or even excused in their actions when they began to conquer other nations.
Did every other person from a former major european power get abit uncomfortable when you read that?
Britan, France, Spain, Russia, Portugal et al...
Hell the good old US of A is built on the Native American's land isn't it?
It is important to note that most of the major European countries, and the United States, have a history of violent conquest and subjugation.
It's also important to remember that that trend was winding down in the post-World War I era; people were starting to really see that that was wrong
and unsustainable. And as such, it's also important to remember that Hitler, Mussolini, and the Japanese were not only being immoral by seeking to conquer the world, but were also showing that they were behind the times as the world's liberal democracies began to realize that imperialism is evil.
It's also important to recognize that the Axis powers were pretty unique in their desire to quite literally conquer the planet and divide it between the three of then.