This is interesting. Right now TSMC seems to provide Taiwan with guaranteed US protection because they are so far ahead technologically. Apple, AMD, and the defense industry have little alternative if they want a cutting edge node. It's unclear how long they will maintain this dominance.

Maybe the long term US-Taiwan ties of factories in the US will make this worth it strategically.

I assume that all R&D will remain in Taiwan. I think this might still be a good move in the long run since it'll give more politicians stake in what happens to Taiwan (Arizona senators, etc).