Are you getting this from Taiwanese? My wife recently spoke with some that joked they were basically there for the taking. They could now.Not even the Taiwanese are afraid of China.
China has never successfully invaded Vietnam.
Klein is correct that China is waging psychological warfare about Taiwan against Taiwan and the West, and it appears to be working very well in the United States. The US seems susceptible to it because (1) the media is sensationalist, and (2) many politically active Americans on both the left and the right like to fantasize about war. Most Americans I speak to about it over estimate the size and immediacy of the threat posed by China to TW compared to what people here in TW think. However, China is not a "paper tiger" doomed to fail, and poses a very real and increasing threat to Taiwan. It's a real problem for us here and has been for awhile. While large gaps in their military and economic systems remain, they are modernizing rapidly and have made a lot of progress in the last 20 years. That said, both Taiwan and China are real places full of real people and most US based analysis fails to understand the situation because it reduces them to pieces in a war game.
The whole issue around China is we believe their hot takes. The facts on the ground do not support the Chinese interpretation of events. The United States has sold arms to Taiwan since Chiang kai-Shek landed. China's military has shrunk by 40% since their last conflict with Vietnam.They could now.