Xi is more right than wrong.
He, or Trump, are both absolutely correct.
Korea was either directly ruled or a self-governing client-state to China, owing obeisance and tribute, over most of its history pre-1895, going back to its conquest (108 BC) during the reign of the Wu Emperor (Han dynasty).
This is, understandably, a delicate issue to Koreans. They have enormous chips on their shoulders vs both China and Japan.
Koreans for most of their history used Chinese as their official written language. And even now many Koreans make the claim that they are true legacy of the ancient Chinese civilization that the people in China have lost.
If Trump said the Chinese president told him that, he’s covered.
I worked for a company years ago that had a number of Chinese software types. In our engineering group we had two young guys who were Korean. They would literally walk with one shoulder rubbing the wall as they passed each other in the hallways, avoiding all eye contact. Sitting with our guys in the cafeteria and just a few tables away, about a dozen Chinese... You could cut the tension in the air with a knife.
What the Chinese didn't know was that one of our Koreans could speak their language. My ignorance here, I wasn't aware of any difference but assumed there were some dialect distinctions. Our Korean buddy would tell us all the disparaging things they were laughing and joking about at the expense of both our Koreans AND American employees, black and white. Everybody was fair game to them.
“Xi is more right than wrong.
He, or Trump, are both absolutely correct.”
Utter nonsense.
Your own recitation of vassal state status refutes your initial statement.
Korea was never part of China.
Korea was, though, part of Japan for a time.