How are we supposed to prevent adversaries from making their communications impossible to intercept? It's not like knowledge about cryptography suddenly vanish

How are we supposed to prevent adversaries from making their communications impossible to intercept? It's not like knowledge about cryptography suddenly vanishes. And it's not like those computers aren't annoyingly programmable to do such evil deeds like encrypting data in a way that officials can't access it. Given that, what's this all about? Governments could mandate key escrow (which is what I guess they're really aiming for) for any system under their control. So adversaries build their own, in Excel using VBA, if necessary. There is no way to honor that demand by the US and UK governments unless computers become a _much_ different thing than what they're now.