Great question.

As a data point, Purism has worked on USA supply chain for their cell phone (Librem 5), and currently ships with mixed-origin parts. "We use US companies with US fabrication whenever possible. Most distributors are based in the US with the exception of large integrated circuits that are made in a variety of countries where those companies do fabrication (US, Taiwan, South Korea, Japan); an example is the NXP CPU we use from their fabrication in South Korea." <https://puri.sm/products/librem-5-usa/#table-of-origin>