I'm a little late to reply but the blunt answer is "because it wouldn't be worth it." To clarify, the point I was making wasn't that tribalism is actually desir

I'm a little late to reply but the blunt answer is "because it wouldn't be worth it." To clarify, the point I was making wasn't that tribalism is actually desirable, simply that if it's ethically agnostic then entrenched and powerul tribes benefit more from its perpetuation typically. For the thought experiment, creating a United States of the World would require either literally taking over the world or some amount of agentic sacrifice from every nation absorbed into the uber tribe. The case for California is similarly unrealistic but for different reasons, you can choose to occasionally give a member of a tribe lopsided benefits and deny them at other times. This is especially true when the alternative is compromising the perceived security of people who are already members of the tribe. Put more succinctly, the California idea is bad because it would lead to infighting and can be handled in a non-binary fashion.