> That cost is simply too high; no one in China wants to pay it
China was happy to invade Tibet and assimilate it's population.
Hard to believe that a government who claims all of South China sea, large parts of India (Arunachal Pradesh) does not want to expand.
Or do you think people of Arunachal Pradesh are also Chinese?
Arunachal Pradesh is a historic part of Tibet and was part of the Qing Empire before the Chinese revolution of 1912.
When Tibet then broke away from China the Brits got what is now Arunachal Pradesh from Tibet.
Hence the ongoing Chinese claim but the days of any military actions are long gone.
Tibet is not (and was not) defended by a nuclear superpower. South Korea and Japan both have United States military bases and troops stationed there.
I am willing to bet all of the money I will ever make in my lifetime that China will not invade either one as long as they remain under the US nuclear umbrella.