Comment by mlyle
So, there's two factors here, that move in opposite directions:
1. China is less likely to secure a semiconductor advantage over the West, if TSMC has a US location. Instead, China is likely to take out the nearby, high quality fab, and whatever they are left with domestically is more likely to be inferior to distant capabilities.
2. Because of #1, China is less likely to secure a massive advantage over the US by invading Taiwan; as a result the US may feel it less likely to support Taiwan.
I'm inclined to think #1 is the more important one. #1 makes the risk of an invasion much higher. #2 makes the reward for an intervention somewhat lower, but I don't think it changes China's calculation of how likely the US is to intervene that much.
How china would secure semico advantage by invading Taiwan? Those fabs would be damaged or destroyed