I'm not arguing that torture is ineffective. (which it probably is) I'm arguing that if we as a people start destroying our very identity, if we start destroying everything good about us as a culture, people, and country for the sake of the easiest victory, then the very reason we are fighting to preserve ourselves is meaningless. If we continue that, what we will have become as a people at the logical conclusion of that course will be nothing both the hollow corrupted shell of what we once were. We would not only be fighting to preserve something that is no longer worth fighting, at that point it wouldn't even exist at all. In essence the bad guys will have won at that point. Even if it's not in the way they thought would happen.
Yes, if as a people if we start condoning torture, the ending of human rights, or other despicable things in the name of victory it will keep going and effect our very essence. It's not just the government doing it, it's the people that let the government do it also. If we don't speak out and turn a blind eye to wrongdoing, no matter who does them, then those people are part of the problem. To think that we can just a blind eye and not have it effect us is very shortsighted and false.
As far as how we fight people like that. We defend ourselves, but we uphold our most deeply held beliefs while we do it. We don't become as bad as our enemy. We dig deep down within ourselves and we persevere. We show future generations what we were made of. We make it so our forbearers that came before us and sacrificed for a better world didn't do it for nothing. We do not take the quick and easy way over the right one, even if that might cause hardship, even if that might cost some of our lives.
You can probably understand then why a lot of the torture that is carried out is denied and kept secret. The powers that be realise that if the people knew of this then the argument that the country had failed it's ideals would start a massive unravelling in society.
If the subject remains ambiguous and unprovable, the state can maintain that the country lives by higher ideals than it's enemies. It can publicly champion communication and negotiation whilst at the same time covertly tackle combatants on their own grounds of menace and terror.
I'm afraid to say I think this is a common practice among most modern countries. As an example, how often do the police get caught handing out unnecessary force on perps.?