plus, it's hard to compartmentalize science. Once you get the bomb, it's not that hard for other people to figure out. So do you ban all German scientists and get the bomb 20 years later (and maybe let the Russians poach them, because...well it is a market with demand...), or get the Germans, and lose a few to espionage/traitors.

I feel these national borders on comms equipment will eventually be a paper tiger of sorts, because, well, tech is tech, and it's hard to stop the flow. And things work best with open standards anyway.