If you haven't yet read the Bloomberg article on how Chinese spies managed to infiltrate US companies by installing their own chips on server motherboards, go read it now. It's a lengthy read, but has all the elements of a spy thriller, and will probably be made into a movie one day.
It does make me wonder if the only way to build truly safe and secure systems is to have everything open-source from the ground up? This could mean using open-source microprocessors like the ones based on the RISC-V instruction set. It may also mean building the hardware yourself. This is not as hard to do for assembling circuit boards as it used to be, but is fabricating your own chips a step too far? Turns out you can fabricate chips in your garage.