I don't agree with most of what you've written, however, if the US has only mineral-profits interest in defending Ukraine from Russia, then there's only slightly above zero chance that the US will be rushing to defend Taiwan from China. What seems more likely is that the US will agree to let China take Taiwan in return for allowing the trade of TSMC chips to continue.

TSMC is the majoity (only?) value proposition the US has in Taiwan, and, from memory and a cursory Wikipeding, it seems that TSMC has been 'de-centralising' into Japan, the US, and Europe of late.