Empires need a reason for expanding. If the inside is the same as the outside, there is absolutely no reason at all for the empire to expand or to exist at all.

Empires need a reason for expanding. If the inside is the same as the outside, there is absolutely no reason at all for the empire to expand or to exist at all. Most imperialistic nations also come with a nationalistic sense of exceptionalism. While the Chinese might have a sense of exceptionalism, Americans also do, as well as many other countries. The Chinese have objectively received many humiliations historically and it is understandable if they do not feel good about it: https://en.wikipedia.org/wiki/Century_of_humiliation https://en.wikipedia.org/wiki/Century_of_humiliation