The USA is also willing to defend Taiwan and currently the US has carrier groups in the south China sea. This suggests that the idea of building chips in the US may be a diplomatic courtesy and arguably an incentive.
Our willingness to defend Taiwan doesn't mean a war wouldn't disrupt the supply chain. There's a reason the Soviet Union built factories in Novosibirsk, and it wasn't because they weren't willing to defend Leningrad.
They moved most factories from the west, not build initially. I am from other Siberian city known for moved factories from western cities during the war.