There are many sole source fab suppliers in TW, Arizona fabs will run out of inputs and shut down. There maybe effort to fully indigenize TW semi supply chain outside TW, but I've not heard any credible policy/efforts.
There is scenario where US incompetence will negate security dilemma, but see how hard JP is hedging. I would not put money on it. The additional layer to this is US security architecture of of East Asia is not just US basing, but US hardware in general... forcing region to no longer operate US platforms that gathers intel for US MIC / break region interoperability (including data sharing) with US. PRC unlikely to convince JP/SKR/SG etc to abandon F35s politically (because alternative worse vs PRC), at least within lifespan of platforms. That requires glassing hardware and coercing alternate procurement.