your 'interpretation' of chinese modern history to my chinese guest
It's no interpretation - just a recounting of historical facts. China is historically not belligerent/aggressive. With their view of themselves as the center of the known universe, they are incredibly incurious regarding what happens along their periphery. They are even less interested in invading someone.
Taiwan, after all, is an island full of Chinese people that evacuated there in 1945. Literally the same Chinese people on both sides of the Strait. Yet, China has not attacked them, and probably will never attempt it. China patiently waited for Hong Kong and Macau to be transferred back peacefully - two territories as historically Chinese, as St. Petersburg is Russian.
One has to admit - Russians are quite literally the opposite type of people. We don't have such high confidence in ourselves, that we can afford to be ignorant of what goes on outside our borders. We've always been very curious and simultaneously paranoid about our neighbors.
Finally, and this is a rare admission for a Russian - it's only ever been Russia that has preyed on China, and never the reverse. Would it be fair then, in this context, to discuss potential Chinese invasions of Russia? Shouldn't it be the Chinese, that are more wary of Russian intentions?
The Chinese are smart, unlike us. They don't need to invade Siberia to own its riches. Russian state companies are busy piping Siberian gas to China, and cutting down Siberian forests for lumber for export to China. Chinese merchants are successfully trading in Russian markets, to the great chagrin of the locals.
China gets everything it needs from Siberia, without having a single soldier there.