Further suppose those agents start breaking the guy's fingers and he spills his guts about how to disarm the bomb and they disarm it.
— RogueAI
His fingers and toes are all broken, and he still doesn't know how to disarm the bomb, because he didn't make it or arm it. He doesn't know who they are or where they are. The terrorists are smart enough to send an ignorant mule to plant it. — Vera Mont

Yes, but suppose they catch one of the smart guys one day...

One ought to assume that sometimes torture is efficacious, otherwise no one would ever be tempted. One thing it is efficacious for, is to instil terror, for example; it functions as a deterrent.

It is not immoral to torture people because it is ineffectual; that is an argument of despair one resorts to with the totally amoral, to whom moral arguments have no meaning. Hurt and harm imposed on another are the basis for calling it immoral. And if hurt and harm should not to be imposed on us, then it should not to be imposed on them either. This simple principle is why the first step in any crime against humanity is "dehumanising". This produces "edge-cases".

Yes, but suppose they catch one of the smart guys one day... — unenlightened

Since they never know whether the latest capture is a smart guy, a mule or an innocent bystander, they'll have tortured and maimed two dozen people before they get any useful information, and by then the information is no longer useful.

One ought to assume that sometimes torture is efficacious, otherwise no one would ever be tempted. — unenlightened

Sure. You can get any midwife to confess having sexual congress with Satan, and you can get POW's to babble on whatever tanks or cannon they may have seen going in what direction, and once in a while you catch a spy who can give up the names and locations of other spies, whom you can then trade for your spies that they've captured and tortured. And if it accomplishes nothing except the suffering of the torturee, there are still many torturers who'll volunteer to do for the pleasure.
If torture had been an effective deterrent, uprisings, resistance movements, heresy and political intrigue would have ended five thousand years ago.

It is not immoral to torture people because it is ineffectual; that is an argument of despair one resorts to with the totally amoral, to whom moral arguments have no meaning. — unenlightened

True. It's meant to counter the argument by the righteous that it is "more moral" to use torture than to refrain from using it, when the agony of one person may save the lives of many. (It is a belief held by many cultures, each with a strict moral coda; Christianity itself is predicated on that idea.)

Hurt and harm imposed on another are the basis for calling it immoral. — unenlightened

Yes, but living by that principle is inconvenient. People will find ways around it and still claim moral ascendancy.

living by that principle is inconvenient. — Vera Mont

Indeed, that's why only the virtuous do it. Even Trump/Putin/the boogieman will tell the truth when it's convenient.

Even Trump/Putin/the boogieman will tell the truth when it's convenient. — unenlightened

I'll wait, but i won't hold my breath.