Indeed; there are a number of sources that indicate the unreliability of torture.
The U.S. Army's own field manuals (link to one above) state that:
"Experience indicates that the use of force is not necessary to gain the cooperation of sources for interrogation. Therefore, the use of force is a poor technique, as it yields unreliable results, may damage subsequent collection efforts, and can induce the source to say whatever he thinks the interrogator wants to hear."
The debate around torture has been intensified after 9/11 and the revelation that U.S. jailors may have used "aggressive interrogation" techniques; a good summary is here:
CIA, FBI, U.S. military officials all seem to concur that torture simply fails to produce results. Ken claims this happened "all the time". Actually his exact words were:
"If you read my post, I personally do not like the idea of torture or any break of agreements to protect civilians and combatents. My point was that it was broken on hundreds of occasions that you may not be aware of. Many of the reasons for these breaks were pivotal to operations. One major operation you may have heard of, OVERLORD, utilized methods by secret organizations you might find distasteful. Threat of execution, execution, assassinations, sabotage, destroying the lives of people by creating false happenings etc, etc, etc. You are very nieve to think this did not go on and you are (naive)to think that these things were not done to WIN regardless of how they might look to people like you."
But this is not "proof" in itself that "dirty methods" (to use his term) was "necessary", for to prove that, he would need to document first an instance in which torture or some other illegal method of extracting information actually had an influence on the conduct of the war, and then he would need to demonstrate why that result was unobtainable by other means. He's simply feeding his own right-wing need for justification with a lot of rhetoric until he's done that - "the ends justify the means" was something the Nazis said.
Ken also mixes up what I would consider legitimate acts or war (sabotage and destruction of war materiel) with war crimes (torture and murder) in his comments. Perhaps if we could obtain a laundry list of those "distasteful" things that were done to "win" in Normandy that he talks about, they might form a better starting point for the discussion. I suspect I would agree that many of them were not that distasteful. But I also get the impression some of them are vague notions more than documented events.
My point was that D-Day was in the end reliant on the logistics of it all - the 7,000 ships, the 6 divisions of infantry, the 3 airborne divisions, the airplanes, the gliders, the months and years of training, the (mega-)tons of supplies in the U.K., the eight navies involved in ferrying them to the shore, etc. and that I would challenge him to produce evidence that a single tortured German prisoner produced a single thing of value to the effort. I don't doubt the role intelligence played, including secrecy, but the challenge here is to ask if any of the items from his "list" never happened, would the entire enterprise have failed? I look forward to his response.