Some powerful points there, Bob.
Your examples of the horrific torture perpetrated in Vietnam outline perfectly the difference I was trying to show between psychological techniques used by the likes of the CIA and outright cruel violent torture used by others.
The world isn't black and white, there are shades of grey. "Torture is wrong, end of" is probably a phrase we can all agree with, but exactly what constitutes "torture" is not as black and white. My old Tp Sgt had worked in the Internment camps in N Ireland at the start of the Troubles. He said how they would encourage splits among the prisoners by for example, salting the food of one, but not the other, thus causing fights over the food. Compared with being whipped with a fan belt for 38 days, that is so mild as to be not even worth talking about. But it would cause a Guardianista a lot of hand-wringing.
I don't advocate excessive violence in the treatment of prisoners, but I don't think it realistic to expect that they simply be put in a cell and not interrogated. Interrogation isn't supposed to be a job interview. What is the "RE" part of "SERE" all about? And who runs the courses? And why do we have such people in the first place?
I come back to my position - it is not black and white.