Why not torture

Slate's Michael Kinsley, in arguing against legalizing (and regulating) torture says

The trouble with salami-slicing is that it doesn't stop just because you do. A judicious trade-off of competing considerations is vulnerable to salami-slicing from both directions. You can calibrate the viciousness of the torture as finely as you like to make sure that it matches the urgency of the situation. But you can't calibrate the torture candidate strapped down before you. Once you're in the torture business, what justification is there for banning (as Krauthammer would) the torture of official prisoners of war, no matter how many innocent lives this might cost? If you are willing to torture a "high level" terrorist in order to save innocent lives, why should you spare a low-level terrorist at the same awful cost? What about a minor accomplice?

I must admit, I find the moral soft-headedness Kinsley displays on this point (along with other so called "Geneva Convention" adherents") disappointing.

The reason you might OK torturing unlawful combatants but ban torturing official prisoners of war is to encourage combatants to fight lawfully--ie. in a way which minimizes civilian deaths--not unlawfully. Soldiers wear uniforms, stay away from civilians, and have a chain of command who can order a surrender. Terrorists hide amongst civilians, using them as shields putting them in danger, and have no authority who can accept a surrender (or give one) on their behalf. Therefore, anything which makes fighting as a soldier instead of a terrorist desirable is good -- good for civilians.

Kinsley apparantly does not consider the effect that blurring the line between soldiers and terrorists has on civilian populations. He correctly identifies that "Torture is like almost every other issue: It involves trade-offs between the rights of individuals and the needs of society" and then refuses to even contemplate those very principles - both moral and practical.