Well said. If we hang some Iraqi intelligence officer for torturing a POW we had better have our own ducks in a row, otherwise the result is indistinguishable from "might makes right."
It is certainly a tough question. I would not want to endager a single American in order to protect all of Al Qaeda from mistreatment.
That said, I can't think of any nation that would avoid using torture in EVERY circumstance. Also, where is the line between putting pressure on a guy and torture? I guess I should look at the Geneva convention myself.
My own personal view is that anything that causes physical injury severe enough to last more than a day or so would be precluded. Water, light, some deprivations and possibly other forms of motivation would be accepted.
You take a guy and put him on rice and water for a month in isolation. Then you take him out and place him five feet from a table with steak, turkey, strawberries, vegetables, mashed potatoes, or some other quisine more in tune to his national norms. If he won't open up, but him back in isolation.
I think there are ways to motivate without physically or mentally imparing a person long term.