The Republic of China has something the US wants. Ukraine is just cannon fodder for DC’s project to destabilize the RF. They don’t give a shit what happens to Ukraine as long as it’s expensive to Russia. They don’t give a shit what happens to the Republic of China, either, and it’s likely that as soon as the US has equivalent chip fabs (if the US is even capable of building something that complex, which is an open question) they’ll either drop or significantly scale down their support for the Republic of China.