I've always thought there's some geopolitical chess at here. The US can't abide being completely dependent on the island of Taiwan. So if TSMC wasn't willing to do this, the US might fund an alternative. This could leave Taiwan no leverage at all.
Now, with some US based production, TSMC is still in charge, and more resilient to disruption. So it may still be a very strong move.
I am not sure if Taiwan has any real leverage. If Taiwan is destroyed or otherwise compromised by China, the US would probably seize the American branch of TSMC, force the sale of the American branch to a western company, or force TSMC America become an independent company.
Isn't that like China seizing an iPhone factory and declaring that they are going to make the next iPhone? I doubt that a TSMC US fab can function independently for very long in the case of invasion, the Taiwanese govt presumably did this calculation before signing off on it.
Reactions to active conflict have a different threshold than normal civil operations. The interests of the US are biased towards continued peace. War is inherently value destructive (even if the military industrial complex gets to sell more stuff for a bit) so a majority of the population from a multitude of perspectives would rather remain fat and happy with their circuses (sports-ball).
That balance changes, as it has since the dawn of western history times, when outside forces disrupt the regular machinations of the people. When events like Pearl Harbor, the turn of the century terrorist airplane hijackings that turned them into missiles and America's citizens into hostages to our own national security theater paranoia, or some country turning the place all of our iPhone and computer brains are fabricated in into a war zone.
> fat and happy with their circuses (sports-ball).
You are protecting your ego. The modern circus is the algorithmic feed. And we are consuming it more obsessively then any previous form of entertainment.
It’s looking really bad for Taiwan to be honest and I don’t think the US has the political will to face off a full on invasion of China against Taiwan. Our military could handle it, but I don’t think the public will is there. I don’t think that China will come away with much other than more land though, the Taiwanese will not hand over their factories and IP to CCP companies, they will blow them up.
Any conflict would leave the small island looking like Gaza, a pyrrhic victory for everyone involved -- if you're trying to seize more than land. It's conceivable that the country making islands in the SCS would see a mere land grab as a win, doubly so if they can weather the global hit to chip production better than their rivals. It's untenable for the US to have so many critical eggs in such a vulnerable basket.
Now, with some US based production, TSMC is still in charge, and more resilient to disruption. So it may still be a very strong move.