Part of the mental maturity process is being able to see the greater affects of the policies of one's country on the wider world, and advocating for policies which enhance things for the greater world while still being positive for one's own country. That maturity process is naturally short circuited in authoritarian countries like China.
Authoritarian China controls both the education, media and internet. It can and does fan the flames of ethnonationalism for political purposes.
The propaganda is usually reasonable sounding, but actually incorrect reading of history.
The more nationalist individuals make their own decisions and are encouraged to be themselves propagandists. Especially spreading propaganda towards other ethnically Chinese people but also to the wider world.
The infectiousness and effectiveness of this propaganda is actually quite fascinating to observe.
Everywhere on the internet there are examples of this information warfare.