Is Czechia historically and culturally German? Sort of.
Is Ukraine historically and culturally Russian? Sort of.
Is Pakistan historically and culturally Indian? Sort of.
Once you have to ignore the wishes of the population and resort to historical arguments, forced reunification becomes a conquest.
I certainly wouldn't like my own government to start expansive wars into, say, Silesia, because it used to belong to the Czech crown for 500 years. But I have a say in this. The Chinese population might not.