1) people are generally what you and I would consider immoral (they support murder/rape/slavery) but also 2) an immoral society can out compete moral societies
In my experience and historical research - self determination is not the human default. In situations where there is no king, groups will appoint a leader from among them.
Self-determination being “free choice of one's own acts without external compulsion?” Or right to choose “their sovereignty and international political status”