The reasons for people to live in the same country

Why should people live in the same country or should be “united”?

Han Chinese think it is because of history. Because

1. our ancestors had ever lived in the same country
2. we are ancestry of the same

So, Han Chinese think all of Han Chinese in the universe should live in the same country, and they call it uniting.

And they think all of the territories occupied by Han Chinese should be the part of China.

And they think it is why Tibet, Southern Mongolia, Taiwan, Manchuria, …, should be part of China.

But their reasons can’t be used to explain why they didn’t want to live in Mongol Empire, or Manchu Empire, or Russian Empire, or Japanese Empire, …. And they should be united into Mongolia, Russia, Japan, … if their reasons are true.