So, I worked for intelligence agencies for much of my early career, and my wife still does, and I get the impression Hacker News fundamentally misunderstands their mission and the way they operate. This sort of effort involving wiretaps and backdoored encryption with state access to service providers is a law enforcement capability, not an intelligence agency capability. Intelligence agencies do not operate within the law and they largely don't care about things like CSAM or internal political dissent. That's the FBI and other part of DHS's concern. Intelligence agencies are at least somewhat constrained in what they do domestically by cleared legislative oversight committees, but internationally, they do whatever they want. They don't need warrants. They may often have, but certainly don't need, the cooperation of governments or law enforcement where they operate. Their tools aren't legal tools. They may use device-level compromise, remote sensing technologies the commercial community and general public doesn't know exists, human spies, and these can be used against foreign service providers or against specific high-value targets directly.

Whatever the law says law enforcement within your own country can or can't do has no bearing at all on what foreign intelligence agencies can do.

All of which is to say, if you're thinking of things like MK Ultra, nobody ever publicly argued we should give that kind of capability to the CIA and it was already illegal at the time they did it and they did it anyway. Trying to make telecom service providers legally obligated to provide an encryption workaround for law enforcement is a completely different thing.