The easiest way to get TSMC's R&D in the US is to have them build a fab here and have employees here. If China invades Taiwan, and TSMC has employees that want to flee to somewhere else, the US would be the most logical option. If they already have a fab here, an established workforce and infrastructure here, that's better than having to start from nothing.

Taiwan as a country doesn't want that. There is a reason they only fab their latest and greatest chips domestically in Taiwan. It is of Taiwan's national interest and of TSMCs interest to do everything they can to ensure that the US protects them from China.

Again, it is a net positive for the US to have TSMC manufacture chips on US soil, so I am not arguing against that point, I simply posit it is not enough from a US national security / technology leadership standpoint.