Well, history said otherwise. Just one among uncountable examples: https://en.m.wikipedia.org/wiki/Sand_Creek_massacre Recognize our 'sins' and don't repeat them, is the best way to improve ourselves. It works for a person, a family or a country. Anyway I (partly) agree with the assumption that most of the land in the world has been stolen from one people to another at one point in history. That's doesn't change the definition of steal. It's like saying that everybody more or less steal, so it's ok to steal. Principles/values should be independent of widespread behavior and habits.