I read somewhere some time ago (can’t find it now) that the optimal size of a nation to be governed effectively, meaning according to the interests of most of the nation’s population, is around 12 million.
And that’s only on the national level. Such a nation would have even smaller political units to govern locally.
If that’s true, then 300 million is about 25x too much, let alone 1+ billion a la China and India.
Do I support secession? Yes, right down to the individual. Nobody should be forced into a political association that they don’t willfully and dutifully chose to associate with.
Maybe that’s the root of the issue for most of the world’s conflicts. What do you think?