There was a meme going round of a network diagram that layers a Chinese firewall behind a US firewall behind a Russian firewall so they can all block each other countries backdoors.

They'll have a lot of work to do, if they want to catch up with the amount and rate of "hidden authentication backdoors" all those companies (and also Cisco) have. E.g. https://www.thestack.technology/cisco-hard-coding-passwords-...

Not sure if you're joking, but both have already done so. And any US company is subject to secret orders forcing them to implement a backdoor if demanded.