Here are the doctrinal references, from American sources (Training and Doctrine Command, but widely adapted under NATO standardisation agreements); all of these were still currently in force at the time that I retired (except perhaps for field manual 27-2, which was up for revision although I don't know how far that got). None are classified. If I can find online references to these I will send them presently; but for now, this is a start.
Field Manual 27-2, Your Conduct in Combat Under the Laws of War, Nov 1984. This manual explains the Law of War in very simple terms and highlights those laws that soldiers are most likely to encounter.
Field Manual 27-10, The Law of Land Warfare, July 1956, combines into one document a complete text of the Geneva/Hague Conventions.
Field Manual 19-40, Enemy Prisoners of War, Civilian Internees, and Detained Persons, Feb 1976, provides guidance for the treatment of detainees from point of capture, through evacuation to internment and release from captivity.
Training Circular 27-10-1, June 1979, Selected Problems in the Law of War.
Training Circular 27-10-2, September 1980, Prisoners of War.
Training Circular 27-10-3, April 1985, Instructor's Guide to the Law of War.
I used to have copies of all of these in my working library: when I retired, I passed them back to folks who were still serving, and who would find them useful (none of these were universal issue for us, owing to budget constraints). The 27-series TCs were meant for company, squadron or battery-level training exercises, typically for 'tailgate training' in theb field. The idea all along was to put the ground rules in simple, comprehensible and teachable form. Nowhere in there was maltreatment of prisoners ever suggested, advocated, or permitted; contrarily, the case-studies and problems presented explained why, despite occasional severe provocation, the rights, dignity and well-being of prisoners and other detainees was paramount.
If the command guidance has changed recently, and it might well have, in my deeply-held opinion this was a change to the ill. Warfare, to the extent that it is just and conscionable at all, has clearly definable limits. Torture in any way, shape or form goes beyond those clear limits.
Relevant references (edited for clarity)
Field Manual 27-2, Your Conduct in Combat Under the Laws of War, Nov 1984. This manual explains the Law of War in very simple terms and highlights those laws that soldiers are most likely to encounter.
Field Manual 27-10, The Law of Land Warfare, July 1956, combines into one document a complete text of the Geneva/Hague Conventions.
Field Manual 19-40, Enemy Prisoners of War, Civilian Internees, and Detained Persons, Feb 1976, provides guidance for the treatment of detainees from point of capture, through evacuation to internment and release from captivity.
Training Circular 27-10-1, June 1979, Selected Problems in the Law of War.
Training Circular 27-10-2, September 1980, Prisoners of War.
Training Circular 27-10-3, April 1985, Instructor's Guide to the Law of War.
I used to have copies of all of these in my working library: when I retired, I passed them back to folks who were still serving, and who would find them useful (none of these were universal issue for us, owing to budget constraints). The 27-series TCs were meant for company, squadron or battery-level training exercises, typically for 'tailgate training' in theb field. The idea all along was to put the ground rules in simple, comprehensible and teachable form. Nowhere in there was maltreatment of prisoners ever suggested, advocated, or permitted; contrarily, the case-studies and problems presented explained why, despite occasional severe provocation, the rights, dignity and well-being of prisoners and other detainees was paramount.
If the command guidance has changed recently, and it might well have, in my deeply-held opinion this was a change to the ill. Warfare, to the extent that it is just and conscionable at all, has clearly definable limits. Torture in any way, shape or form goes beyond those clear limits.