To me the problem with torture isn't that it's "bad". It's that it doesn't serve a useful purpose and serves many counter-purposes. If it wasn't so clearly useless, I'd have to think a lot more about whether I'd support it.
Ok, we'll start with you.
This had better work!
The fact that by massive voting imbalance those few being tortured would have 0 chance of stopping it does not begin to describe the injustices inherent in your proposed scheme.
Ethics and principles are hard to reconcile with statistics and calculations, by suggesting that there is a greater good for which you will discard your principles in a heartbeat you are devaluing everything.
The question then becomes where do you draw the line?
A few individuals? A few tens of individuals? A few hundred? A few thousand? As long as it is one person less than would be killed otherwise?
Best not to make that first step and stick to 'torture is bad, no matter what the upside'.
Where do you draw the line therefore zero is a standard approach from the nays in almost any policy debate, but it is easily defeated. I draw the line somewhere. Not sure where. I'd have to figure it out if I ever heard evidence that Convinced me torture is useful.
There's a possibility (IMO, a certainty) that torture isn't 100% effective, and there's some number greater than 100 of deaths that I'd need to avoid a year from now to torture 100 people today. (some of those 100 might die anyway before the terror event; we might thwart the terror event via some other means; the terror threat may itself disappear [death of those terrorists or other means])
It's just another case of "pay me $1MM today and I promise to pay you back exactly $1MM in 20 years"...
Effective at getting information? Probably. As torture is primarily used for interrogation, torturers would stop torturing if it didn't work.
But I guess it's a bit like bombing a village where you have seen Talibans two hours ago. Sometimes you will kill the Talibans. Sometimes you will kill Talibans and civilians. Many times, you'll just kill civilians. For instance, during the Algerian Independence War, French intelligence intoxicated the FLN by making them believe they had been infiltrated (operation KJ-27, January 1958). The FLN commander in the sector tortured the suspects, which promptly gave names of people they knew, which in turn got tortured, and so on. This resulted in the elimination of (at least) hundreds of combatants, most of whom were actually loyal to the FLN.
I don't know if that follows
that argument can be used to defend the logic of any illogical act
specifically with torture, there are cultural pressures to "do everything possible" that override considerabtions on whether it actually works
You can find historical examples of torture working for the goal of acquiring information. For instance, the battle of Algiers is well-documented. Any asymmetrical conflict has involved torture.
Obviously, any perceived benefit on the ground is counterbalanced by the loss of moral high ground, worsened perception by the local population and occasionally, international condemnation.
Getting information, I'd say not very effective. The issue is, what if the person really doesn't know? How do you tell the difference? You listed some examples, but how did you confirm that this information was true and not just bullshit these people were saying to make the torture stop? In the end, weren't the "loyalists" just killed anyway? Maybe they weren't actually loyal so they were simply killed and logged as loyalists. Since the main "evidence" is testimony under extreme duress there's no way to know for sure.
2. To me the problem with torture isn't that it's "bad"
Hmmm, have you tried losing an eye? That's should be quite bad.
This type of reasoning is used in all sorts of military actions, like drone strikes.
Armong the many problems with it: in practice it never works out that even a simple calculation of whatever action saves net lives should be pursued. Instead, policy makers operate with wildly different valuations of individual lives. Roughly, the ration of the value of one american life to one foreign national of a Muslim persuasion seems to be about 100:1. This leads to very steep slippery slopes and resulting atrocities.
That's just one problem with your views, which are thoughtless and crude.
If you want to "solve" terrorism, first of all, you stop all the bullying, controlling, exploitative, and to summarize trouble-making, foreign policies.
In spite of what the USA agenda and propaganda dictates, terrorists attack for a logical reason (of course, this doesn't mean a reasonable one), not because they wake up one morning with the intention of bombing the population of a given country.
To answer your question more directly though: torture and grey-legal area practices are ineffective because they are already put in practice. There's plenty of documentaries about this, and by the way, a short time ago has been posted a link to the Guantanamo prison practices here in HN.
I mean, you make a good point that it torture doesn't work (well, it actually does work but only for it's original purpose: to get people to claim they did something that we need them to claim they did, even if they didn't), but personally I don't want to know if it works or not because it's not valid no matter how effective.
Edit: I mean, even if it were useful, is is acceptable? Probably not.
Which would be a quite interesting level of emotional hypocrisy, given that we tolerate far greater damage to far larger number of individuals on a regular basis in the name of security.
Consider the number of civilian dead from the Iraq and Afghanistan wars, for example.