TSMC's lithography machines come from ASML, which is in the Netherlands. I always find it surprising that people talk about TSMC so much and not mention ASML; people talk about "TSMC's 5nm process", but it's really ASML's tech that powers all of that.

Setting up a new factory to replace TSMC is not trivial of course, as it's operationally hard, but none of the core tech would be "in China's hands".