You work with us, you get benefits, you work against us, you get punishments. THe US opted for (a) fear, (b) threats (d) discomfort (e) stress. They didn't use pain receptors as the basis for their torture. That is clearly the least authoritarian thing you can do. Any authoritarian government would never not use pain in torture if they have full authority. (emphasis mine)

So you admit that it is authoritarian, just less than those other bad countries, right? And if you use a tautological definition of authoritarian without recognizing that there are shades to it, then yes, you will arrive at an unfalsifiable conviction that US isn't authoritarian (because authoritarian govts torture and the US doesn't ... or some logic along those lines).

Obviously, when the US was starting their interrogation program, they asked the DoJ to give them the LIMITS of what they can do. Those limits given to them were that they can use waterboarding as fear simulation. That's a fact. They obeyed the law and that's why no one was prosecuted, not even by the Obama administration because no law was broken.

You're confusing legality with morality again. Everything that NK does is legal in NK (if not, they're incompetent in writing their laws).

Can you consider the program unethical? Well if you consider this unethical, then you consider ALL interrogations unethical, because every interrogation uses some sort of fear, discomfort, threat, or stress, to induce cooperation from a hostile suspect.

No, don't straw-man my opinion here. I don't consider things ethical or unethical in absolutes. Context is everything. Also words like hostile suspect are meaningless if your definition is going to be tautological again.