[znfi]

This case reminds me a bit about the US embassy in Moscow, where the US let the Soviet provide them with premade concrete pieces for the construction [1]. The idea was that it would be enough to inspect them to detect if any bugs had been inserted.

This plan didn't work out in the embassy case, but I'm not any kind of expert on electronics, so maybe the lessons learned doesn't translate exactly to the PCB situation.

[1]: https://www.nytimes.com/1988/11/15/world/the-bugged-embassy-...