I also worry for Taiwan. If China chose to invade and the first invasion wave were not successfully repelled by the military assets already in the immediate area, other nations might try to intervene but few would be in a position to act immediately. "Defending Taiwan" is a tricky prospect if the PRC already invaded it yesterday; and as you say, possession is nine tenths of the law.

TSMC is a better defense than owning nuclear weapons. But also way more expensive to develop (so not really a good option for North Korea or Iran...). But for Taiwan it is vital to keep the smallest proccess on their land.

The decision whether the West will fight for Taiwan will not be affected by TSMC.

HN crowd absurdly overestimates the need for the smallest node. At worst, the West will have a mildly smaller amount of slower chips for a few years until sufficient investment allows catching up.

Under which legal system? I thought that China was generally able to influence who owns domestic companies pretty much at a whim by nationalizing them, and that chip manufacturing seems like something that many countries might consider nationalizing based on how expensive they are and how critical they are.

Although it seems convoluted enough that if it's not truly critical things get left alone. But chip fabs are probably critical enough that they won't get left alone.

But non-Chinese can’t own a Chinese company. All the Chinese companies on American stock markets are basically just shell companies with a “profit sharing agreement” with the underlying Chinese controlled asset.

That’s why this is an interesting question to me.

It doesn’t feel like we can trust the CCP to maintain the status quo any longer.