I reckon this could be addressed with contractual guarantees in exchange for doing business in the first place. Make it a contractual requirement that the supplier agree to adjudication in the United States in the case of security related concerns or other tampering with the final product or with the designs. They could still refuse if something happens, but I reckon at that point you can just work to shut them out entirely from the US market.

At this point, I think it's fair to establish an industry watchdog group that works as a clearinghouse for knowing all the American companies sourcing parts from the PRC and which companies they source from. This watchdog organization would be responsible for blacklisting suppliers from the entire US market if they don't agree to adjudicate in the US or if they fail to meet that contractual obligation).

This won't bankrupt them outright, but it will sever them from the US and if this watchdog group expands to aid non-US companies, could help shut them out of the entire global market.

I would also require registration of all top executives of these corporations so that you would make the punishment sticky if they moved to other companies. Overall, you've got to set a high punitive cost to non-compliance and non-cooperation.