Chinese can speed up creating local lithography if Germany Zeiss optics agree to help. ASML is just a system integrator and the most important modules is from Zeiss.
If you kill the golden goose, what motivation US has to 'protect' Taiwan? It looks like taiwan politicians are idiots. If their chip business goes to US, there is not left valuable for US to bother about Taiwan. TSMC shouldn't care where they build factories as long as it can keep making money. If it moves to US, no difference to them. But that leaves taiwan with absolutely nothing of value.