I don't think that theory is as true as you believe. China ceded a whole lot of territory to Russia without too much of a fuss. The whole of Mongolia was part

I don't think that theory is as true as you believe. China ceded a whole lot of territory to Russia without too much of a fuss. The whole of Mongolia was part of Qing, and they gave that up. Dittobfor Vladivostok. China's border disputes with India was created by the British, who just draw a line somewhere without consent. China offered to draw turn the Line of Actual Control into the official border, which means China would get about 30% of the land, but India rejected that offer, so now we are at a perpetual border conflict.