> > China is likely to take out the nearby, high quality fab
Yes.
If China's domestic fabs are second best or close --- and China may manage to crawl into this position --- destroying the best fab increases their relative standing and significantly hurts Western security. Whatever crumbs they get from Taiwan (the proportion of expertise that decides to roll over and help, and whatever capital equipment survives to be reverse engineered) are just a bonus.
If China's domestic fabs are not --- because there's a fab tied for first place in North America-- destroying the neighboring fab that they benefit from clearly doesn't benefit them.
