In the popular imagination, torture is the application of pain, often to the point of death, in order to obtain information from an unwilling subject. Torture has been around for thousands of years, and during that time, a lot of mythology has grown up about it. Basically torture is interrogation carried to extremes. The ultimate extreme is killing the subject, which is usually avoided, at least until you get the information. Advocates for the abolition of torture believe that torture doesn't work. Obviously, it does work. Just check out the history of espionage during World War II, or any other major conflict. Torture was accepted, if not much talked about. Information was regularly extracted from unwilling captives, and much damage done as a result. Everyone used torture, even if there were regulations against it. To this day, spies and soldiers are trained to deal with torture. It is acknowledged, in the espionage world, that if one of your people is caught by someone who has torture experts, your guy is likely to talk eventually. Thus there are often provisions for suicide pills.
In the war on terror, it was understood, early on, that there might be situations where you had a captive who possessed life-saving information, and you had to get that data, or lose a lot of your own people. To the anti-torture crowd, that is not acceptable. They believe, as an article of faith, that torture is never justified, and simply doesn't work. How do you argue with this? You don't. You can't. It's a religious argument, and you cannot dispute faith.
What the Department of Defense wants to avoid is getting stuck with a set of rules so restrictive that, when information must be obtained from someone, the interrogators will have to accept the possibility of going to jail if they attempt to get life saving information. That may be end up being the situation, and torture will never be eliminated. But it is possible to issue rules and regulations, if only to keep the media happy and silence the stridently righteous.
The U.S. Department of Defense is having a hard time keeping politics out of intelligence collection. The key issue is interrogation methods, expressed as "opposition to torture". This has become something of a religious issue, and a vague one at that. Pressure groups, both domestic and international, have seized on torture, and its abolition, as a major issue. The problem is, there is no agreement on what, exactly, torture is. To many anti-torture advocates, what goes on in police interrogation rooms worldwide, every day, can be considered torture. The effort to define torture gets mixed up with the effort to outlaw torture. Caught in the middle are intelligence organizations, which are sometimes in situations where torture is the lesser of several evils.