Watch any WWII era American war movie and it was easy to tell good guys from bad guys, The evil, ruthless, immoral Nazis and Japanese tortured captured POW.s, allied spies and local insurgents with abandon. The line was always "You will tell me what I want to know" or "We have ways to make you talk". Nowadays those lines are more likely to be spoken by the fictional TV character American CIA agent Jack Bauer. Right wing talk show hosts and Republican politicians alike love to use Bauer as a model for the hypothetical "if you knew it would save American lives wouldn't you torture a terrorist"?
Well let's look at how that hypothetical might work out in the real world. Let's say you rounded up 1000's of young males along with some suspect women, children and old men in a war zone, like say Iraq. Now let's say we put those rounded up in a prisons like say Abu Ghraib. Now we know they have information we want and it could save American lives and win us the war so what would Jack Bauer do?
Jack Bauer wouldn't worry about any Geneva Conventions when American lives were at stake.
Back to our hypothetical scenario: In the fog of war you will have rounded up 1000's who just happen to live in the wrong neighborhood, been in the wrong place at the wrong time, have a family member engaged in the wrong activity, etc, etc,. So we can assume you will be torturing a lot of innocent people, but let's say you do get some actionable intelligence from a few actual terrorists and that intelligence could save some American lives. Of course you will also get a lot of fake, worthless and bad info because subjects would say anything they thought you wanted to hear to stop the abuse and then there are the fathers, brothers, sons and extended clans of those who were innocent and tortured -they will now be determined to exact revenge and kill Americans to redeem their families honor. Plus any enemy fighter that might have been tempted to cooperate if he knew he would be treated humanely now knows that surrender or cooperation would only mean torture, humiliation and possibly death.
So on balance what did you accomplish? How many American lives have been lost and how many insurgents and enemy combatants have been created as a result of torture? Many more then may "hypothetically" have been saved by it. You might win a battle with torture but you will lose the war.
What is incredible is that we have clowns running for president and being taken seriously who would base our foreign policy and war strategy on a cartoon character in a TV series or a fantasy out of a Rambo movie. Are these guys 12 years old? How far have we sunk? How did we get to the point where it's not the bad guy in the movie saying with a threatening sneer "we have ways to make you talk", it's the American.