Boston Globe columnist Jeff Jacoby, not known for being some kind of lefty squish, lays out the post-OBL case against waterboarding and torture:
I don't know whether waterboarding was indispensable to rolling up bin Laden; for every interrogation expert who says it was, another expert argues the opposite. But the case against waterboarding never rested primarily on its usefulness. It rested on its wrongfulness. It is wrong when bad guys do it to good guys. It is just as wrong when good guys do it to Al Qaeda.
Some Americans have convinced themselves that waterboarding is closer to "a dunk in water" than to genuine torture. In fact, it is an agonizing, terrifying form of abuse. "The victim experiences the sensations of drowning: struggle, panic, breath-holding, swallowing, vomiting, taking water into the lungs and, eventually, the same feeling of not being able to breathe that one experiences after being punched in the gut," Evan Wallach, a former JAG who teaches the law of war at the Brooklyn and New York law schools, wrote in 2007. "The main difference is that the drowning process is halted…. It can cause severe psychological trauma, such as panic attacks, for years." There was good reason why waterboarding was one of the war crimes for which Japanese officers were hanged after World War II.
Torture is unreliable, since people will often say anything — invent desperate fictions or diversions — to stop the pain or fear. That doesn't mean waterboarding will never yield valuable information. […]
Like chemical and biological warfare, torture is something we refuse to engage in, despite its potential effectiveness, on the grounds that it is fundamentally immoral and uncivilized. Our repudiation of torture is absolute — the international Convention Against Torture, ratified by the United States in 1994, allows for "no exceptional circumstances whatsoever." That unconditional repudiation is one of the lines that separates us from the barbaric jihadists with whom we are at war.
The killing of bin Laden was gratifying, but it was no vindication of torture. […] Bush was wrong to permit waterboarding, and wrong to deny that it was torture. I don't agree with Obama on much, but when it comes to waterboarding, he is right. America will defeat the global jihad, but not by embracing its inhuman values.