China is super xenophobic, like many Asian countries.

Those savages. Yeah, that doesn’t sound racist at all, not orientalist at all. Are you Josep Borell?

If China then decided that they want to finish the job on making the Korean peninsula Chinese, who would realistically stop them?

What are you talking about? Koreans are still in Korea, speaking Korean. If it were in China’s “nature” to make Korea Chinese, then why didn’t they do it at any point over the centuries?