Though he believes that waterboarding probably "saved lives", a CIA agent who participated in the procedure believes the technique constitutes torture, and, most importantly, "Americans are better than that."
That's the crucial mark, isn't it? I mean, it's not just Americans who are "better than that" -- waterboarding was beyond the pale for Jim Crow Mississippi for use on Black criminal defendants.
There are lots of things we could do to terrorists and their associates which could conceivably save American lives. We could shock their testicles with a taser, or we could anally rape them with a spiked bat. Shelby Steele advocated prosecuting the Iraq War without worrying about whether given tactics would be seen as "racist" or "imperialist", a policy that, as Spencer Ackerman put it, would define victory in Iraq as "anywhere south of Kurdistan ought to be a smoldering wasteland."
I am skeptical that waterboarding works on a large scale, though there may be specific cases where it gets us useful information (though even in this most recent case, accounts vary about whether we got useful intel). But at some level, this debate is a distraction, because we're Americans, and we're better than this. It's the perils of being the good guys -- sometimes, you got to be good.