So, what you're saying is that you have no proof of the correctness of your belief, you are just assuming that it is true due to emotion.
No, I'm saying that common sense should tell you that it is true and that you fail at being human if you think otherwise.
There is no such thing as common sense.
Logic should tell you that you that it is false.
If all cultures have the right to self-determination, what of the right of self-determination of a culture that determines it wishes to conquer other cultures? In order to respect its right of self-determination, one would have no choice but to permit its aggression.
And if aggression is impermissible, then cultures do not truly have a right to self-determination.
By your analogy, the Nazis would be evil, but the Allies would be equally evil for stopping them.