I have no problem with revenge at all. Torture, well it depends under what circumstances...
As far as I can tell, and from what I have read, there is no reason to torture other than revenge or to instill fear.
We agree that torture does not provide good intelligence correct? It is fact that someone who is tortured or coerced has a breaking point and when that thresh hold is reached he or she will say or do anything to relieve the torment.
That leaves revenge and instilling fear.
Now revenge I do not condone as a state. If someone rapes my daughter, I cannot guarantee that I would not exact revenge. In fact, the chances are pretty high that I would. But a state apparatus exacting revenge is the act of dictators and military regimes. We are a free country whose laws are based on reason and ethics. To exact revenge on innocent people in order to harm a few guilty ones goes against everything this country was founded on and every soldier dies defending.
Instilling fear, now there is a provocative reason. Not only does the state instill fear in their victims (the detainees) but also in would-be enemies and even its own citizens. Yes, we all know that the president now has the power to declare any person, even US citizens, an enemy combatant. That person would be kidnapped and transported to a detention center where we know that torture not only exists, but is lauded by some citizens. People assume that if you are declared an enemy combatant, then you must be a threat - otherwise, why would the president bother?
I'll tell you why, to stop opposition. If ordinary citizens like me, people in the press, civil lawyers, priests and so on were renditioned, tortured, tried and executed the press would label us as spies or treasonists. The public would no longer openly dissent. The administration would not be questioned. People would fear that detainment and torture.
And by the way, the Nazi's did just that. So did Mussilini, Stalin, and many despots throughout Latin America and the Middle East/Southeast Asia.