So i found an ancient ritual, and them improved upon it. I cast the ritual, transforming 8 of our bravest warriors into a form of advanced undead, called wraiths.
Wraiths are incredibly powerful, and have useful magic abilities. They are very resilient, incredibly hard to destroy. However, they can still be destroyed. They take the same damage as anyone else, it just takes much more of that damage to kill them.
Unlike many lesser undead, wraiths are possible to repair from the damage inflicted to them. But the only way to do so is for them to drain the life energy of other creatures (same as with vampires).
The life energy can't just be given to the wraith through other magic, it must pass a process of transformation into a necrotic form, which can only happen when the energy is transferred from a living creature to the wraith. And for the living creature the process is very painful.
If i could create wraiths that heal differently, I would have. But i can't, creating wraiths that can heal at all was hard enough.

Now, the wraiths are extremely useful. They are a big part of our military power (the armies are small enough that 8 very powerful warriors have a significant impact). They prevent a lot of deaths, and a lot of unjust action. I am not sure if it would be correct to say that the survival of the entire city lies on their shoulders, but it's also probably not completely wrong to think so.

This comes at the cost of suffering, because the wraiths must survive. Draining wouldn't be required if wraiths weren't intentionally damaged by war (they are usually very low maintenance), but it is required.
Many people volunteer for draining, sometimes, because they are grateful to the wraiths, and think safety is more important than pain. I often volunteer, because i am a pathological altruist.
But "there are people who volunteer to endure it" doesn't change the fact that it is still extremely painful, which i know from personal experience.

We decided, very recently, on a policy. When possible, we measure how much damage was inflicted to each wraith by enemy warriors, and then drain those warriors, if they are captured, by exactly the amount of life needed to heal the damage they are guilty of. We avoid pointless cruelty. We do not use torture in interrogation (it doesn't really work). But this seems necessary. And is, in a sense, fair, Lawful. The warriors always have the choice to die instead. They are only drained the fair amount, not more. Afterward, they have the same rights as everyone else, and some do in fact become productive members of our society (or just leave, which they have the full freedom to).

But still, "they torture those who were captured or surrendered" ends up being a true fact about us. One suggestion was to instead of the soldiers, drain the leaders, who are at true fault for the fight. Maybe that is better?
And theoretically we can be so honorable and altruistic to never drain the enemy, even if the enemy is at fault for the draining being required in the first place, and it isn't just revenge or punishment, it truly fixes the problem, a compensation for the harm they caused. Even if we don't do that, the draining would remain necessary. It would just make our society worse to live in, at no fault of those who suffer.

It seems to me that it is the right choice, to create a world that is overall better than it would have been otherwise. But i keep thinking i am wrong. That it is a case where the cold pragmatism of ["Darkness"] should be discarded in favor if the idealism of ["Light"]. But i do not see a better solution.

(To clarify, draining life isn't dangerous. Healing living people is easy, we have a lot of potions for that (i am good at making them in bulk). Pain is the main problem. And "we heal you just so that we can hurt you even more" is obviously not a good thing, by any measure.)

INFO:

• does your society not contain any people who like that sort of thing?
• what's the minimum amount of drain that one person can usefully contribute at a time? how bad is it? could you pay large numbers of people to provide tiny amounts of repair each? if there's a small enough amount that it's merely very uncomfortable and not horrifically painful, that could work out better than draining a smaller number of people each a traumatizing amount

"Like that sort of thing"? You mean, sexually? I do not know that much about sexual life. I know some people enjoy being, say, spanked. But...this pain is not sexual. It's your soul...well, being ripped apart, a little. I...can't swear there aren't any people in the world who would enjoy their soul being ripped apart. But they are probably rare. And the population of our city is, depending on the definition, several hundreds to several thousands, we do not have any of those people, probably.
(I had a similar thought, once, that among tactics that are considered evil but may be good, i could make agreements with some demons, the kind who are strengthened by pain, that they help me us and in exchange get pain, but only the kind of pain people are really fine with. I didn't think about any details, and demons are never trustworthy, "I have a great plan involving summoning demons!" is the kind of thing The Inquisition would be right to kill me for. Unlike my completely safe necromantic practices.)

The process of draining is not perfectly consistent or measurable. But the smallest amount of energy a wraith could ever drain is very significant. Or rather, a wraith can drain less, but then the energy isn't enough to do anything, so it's a lose-lose situation. [To heal you must drain at least 3 (GURPS) HP.]
The idea that a small cost for many people is better than a large cost for few people (or the opposite, that making a lot of people a little stronger is better than making only few much stronger) is one that perfectly fits my philosophy, I do believe in it. And I am just now working on systems for distribution of energy. Magical energy, not life energy, but they are similar. It is possible that after many years of research, I could build something that takes small amount of life from many people, and then "condenses" enough that the wraiths can use it.
[Several paragraphs of details about thaumatological engineering omitted.]
But I can't do it now, and I have no idea if it is possible at all. Though I hope with all my heart that it is.

in that case I think that rather than extracting torture from your prisoners you should import some grapes set up some kind of system where you pay your citizens to undergo souldrain
and if they won't volunteer when paid amounts you can afford, this suggests that your system is flawed

They are paid, sort of? Our society is pretty new and doesn't have a fully legible and organized economy yet. But people do get compensated/rewarded for being drained.
By "volunteer" i mean "someone who agreed to", not someone who agreed to only of their great kindness without expecting reward.
That people are getting rewarded doesn't solve the fundamental problem, that suffering is required.

Also, not sure how "pay them" applies to enemy soldiers. Is it ok to drain them forcibly, as long as they are rewarded later? Probably not.
They are, in a sense, considered to have a debt towards the city, for harming it, and draining clears that debt. Having it be a literal formal debt in money, that they can pay for in other ways, really might be better.
Though that in turn might create the incentive and culture of fighting more and finding value in defeating people, which we shouldn't have, the whole point of the "deserved draining" policy is to restore the damage lost in the fighting, and nothing else.

yeah i recommend that, if you choose to construe your captured prisoners as owing you a debt for the damage to your wraiths, you make the debt ~fungible and let them decide how they prefer to repay it

Words echo from the void, moving across unreality...

NTA, sounds like an overall improvement, there will always be some people who think it's not "worth" the "amount" of suffering, but until peace is more sought after globally, it sounds like you're doing an admirable job. are there memory spells or potions you can use after the fact to erase people's memory of the horrible pain?

Memory spells? Hm. I am not good at all with mind-affecting spells. We have some people who can do them, but not very strong ones.
And I don't really think not remembering your suffering makes the suffering less bad? But that's a very philosophical question without a clear answer.
Also, we try to be very careful with mind-affecting magic, because we do not want to become a society built on mind control. Which i know sounds very hypocritical in the context of mandatory draining.
I know there are spells that make you not feel physical pain, though i can't cast them myself. This is not physical pain, and so i think they won't help at all.
But. We should research more into ways to use mind affecting magic to ease the suffering of draining, in various ways. It is a good suggestion. We didn't do it already, because there weren't any low-hanging fruit in that direction, but it is very important, we should try more.
(It would still, i am sure, not make draining completely harmless or painless.)

He was right, creating a shouting-into-void-device Interdimensional Untargeted Communicator was not a waste of time after all!

I’m waffling, a lot, because I don’t really understand what you’re going through, with the war. In my experience people mostly attack others because they've been driven irrecoverably insane and evil by magic. I can't imagine what it's like to have people in their right minds choosing to attack you in an organized way, and I know that did happen to people who weren't criminals a long time ago so I'm not just assuming you must be in the wrong. And I see why it'd bother you to ask this kind of sacrifice of people specifically because they haven't caused problems.

But why would people surrender to you if they'll be made into involuntary sacrifices? I'm not sure I trust that this works out to encouraging peace. And it's so easy to demand sacrifices that aren't worth it when the people being sacrified have no say.

I could change my mind but I think YTA.

"I'm not sure I trust that this works out to encouraging peace. And it's so easy to demand sacrifices that aren't worth it when the people being sacrificed have no say."
Yes, exactly. That is the source of my doubt.
How much say the sacrificed have on the matter is the exact thing we are thinking about now. As said previously, I think it is very important that they have the choice to die instead of suffer, as I consider the right to death to be...well, sacred, essentially. (Context for the rest of the multiverse: on death souls continue to exist, and supposedly travel to realms of gods, though no one knows how that work exactly or what happens to a soul, and I am not 100% sure gods actually exist.)

Also, to clarify, not all enemy soldiers are drained, only those who directly harmed a wraith in the fights. Doing otherwise would have been unfair.
Being fair but not merciful is kind of the theme here.
Also, while i agree with your words, if you live in a context where only people driven insane by magic ever harm each other, i suspect your insights are less useful, because our contexts are incompatible.

Words echo from the void, moving across unreality...

YTA: creating beings who must feed off others to survive is morally abhorrent, must never be done, and is worth letting your society collapse to prevent.
you should let the wraiths decay and attempt to negotiate for peace, or if that cannot be achieved, trade.

 

And that is...also fair. True, partially. I don't like the situation. Civilization is not a sacred goal, that justifies suffering.
But it can itself prevent suffering. And "just negotiate or trade" is also not a real solution, it's easy to say from a different reality.
And technically wraiths cause less harm than an average carnivore, because a wraith that is undamaged, isn't hit in combat or falls down the stairs or whatnot, doesn't need any sustenance beyond a high magical background. But i am making excuses why my actions aren't as bad, and counterarguments exist, it's possible for carnivores to hunt and kill without inflicting the deep fundamental pain of soul-drain. But I don't know if it's actually worse than death. Especially from the perspective of animals, who might have both preferences different than sapients, and maybe less moral value, except how the chaos would I calculate it. Except also...aggghhh!
[Message was left unsent on the Communicator.]

Here ends the thread, or was supposed to originally, but i think leaving the option for people to write in if they have something to write is better than not.

The problem with this sort of thing is always in the messy details. It sounds like you're trying really hard to nail down the edges of your tarp here, but it seems like it might be built on metaphorical sand? A major problem with policies like this is the norms and incentives it creates. It's one thing to weigh consequentialism vs whatever the opposite of that (i forgot) but also you should think 'when strangers hear about us using horrific soul-draining to sustain an elite core of necromantic minions, what incentives and impressions does this give them?' Like your demon thing. It just sounds really awful, anything where you go 'I know how this sounds BUT' is iffy. You know? I would go further than that and say maybe any plan that involves systematic torture should be at least firmly suspiciously squinted at. 'Oh we stopped doing the torture, it was a mistake' is a lot better than 'Yes we torture people, what of it?' From the more squeamish potential allies perspective and for establishing a general trend of less awfulness going forward.

But we chose similarly once upon a time. We invited an apocalypse with all it entails, in order to secure long term gains. So who am I to judge?

NTH

-A fox

Yeah, ideally, there shouldn't be any true facts that make people suspicious of you. On practice, that is much harder to achieve (especially as "necromancy!" is a much more notable for most people then "also painful way for 8 of the undead to heal").
And "yes, we sometimes torture people, but only in a specific predictable way, and only if they attack first, and only up to a specific limit, and for a clear instrumental purpose rather than pure sadism" is...much better than many others can truthfully swear to. Though of course "there are others who are even worse" is never an excuse for doing something bad.
The other coin to being known for evil actions is being known for being very honest and open about anything you are doing, such that, if you did something evil, you would admit it openly, just like you admit the other evil things you are admitting openly. It's a coherent approach. Ideological Lawfulness, that is. Not sure how practical.
(To clarify, the demon remark was about different thing. Not "people will be suspicious, but it's actually fine", it's "if i think it's fine, then i am probably just wrong", because of the, uh, "recursive evilness" of demons. The wraiths aren't recursively evil. They don't try to convince me that draining is fine and there is nothing to worry about. Or that i should create even more wraiths. They are very chill guys, actually.)

I'm super chaotic so idgi beyond the story.

And the story here is 'necromantic monstrosities, but in a good way, I swear'.

Life is hard. Governments are heavy. The wheel grinds ever on.

Yeah...

In my experience, such policies often turn out not worth it, in the end. The benefits are immediate and legible; the costs are indirect and illegible. If you choose to pursue such a policy, I recommend that you do so only after you have a few centuries of experience in governance, and that you take great care for both the appearance you may give to neighboring polities and the precedents you may set for future generations.

Carefulness with appearance and precedents is of course essential.
Centuries of experience in governance are also useful, but, inconveniently, require both you and the government to exists for centuries. Which, unfortunately, is hard to achieve in precisely the kind of hostile conditions that would require such radical strategies in the first place.

[At least it won't end in a Cataclysm like with Lreareth! Wait, on second thought...]

I’m glad you reached out with your questions before you made any major mistakes (as I think some of the other answers might be directing you towards)!

First and foremost, you are not the asshole or the villain in this situation.  You’re an innovator, and you shouldn’t let outward appearances or the reactions of the ignorant to those appearances discourage you!  It’s your society and your (I would hope consensually adopted) rules!

Those enemy warriors did economic damage to you, not only through damaging the quite valuable wraiths you’ve ingeniously created but likely through other harms to your society.  I am a firm believer in the non-aggression principle, but as they’ve caused damage it is only fair and right that you extract value out of them equivalent to the damage you’ve caused.  And as your ritual allows, you can in fact have them pay for the most direct and expensive damage they’ve caused.  If anything not accounting for any other damage they’ve caused and doing more to extract equivalent value (such as through compelling their involuntary labor or using the necromantic arts to extract it from their person) is a warning sign of possible excessive moralistic and unpragmatic tendencies on your part. 

Now, you mention your society doesn’t have a “fully legible and organized economy yet”.  I would recommend working on this as quickly as possible.  With a more legible economy, you could more accurately calculate how much they owe you (and your society) in damages and offer them alternatives on repayment.  With legible economics and payments, you will likely find many people employable for your process!  I have some advice on strategies for hiring people for such processes, if you should like it.

I will caution and advise you on several points of economics and finances in developing a more legible market economy for your society.  Often, many societies allow moralists to impose excessive restrictions on voluntary economic interactions, substantially raising transaction costs.  Likewise, they impose artificial subsidies of certain persons and actions that undercut more natural and efficient economic exchanges.  You seem like an influential person in your society, so I would recommend utilizing your full influence to avert these… inefficiencies.  I can give extensive examples of the benefits of avoiding them and the flaws and waste of societies that embrace them.  Finally, you seem like quite the innovator, make sure your society’s developing rules include a proper accounting of intellectual property so that you will be properly compensated for your efforts.

Oh, and if this unusual mean of communication should fail and leave this my last message to you, remember the power of compounding effects!

As implied previously, strategies of the "enslave defeated enemies" type will make fighting a big incentive, such that, even if the rule is "we never attack first", provoking the enemy into attacking first will become profitable. Which would go against the desired principles. The whole point of draining to restore wraiths is that it doesn't incentivise the wraiths to fight more, is not better than the default state.
Your use of the word "moralists" is concerning too. It's true that sometimes people use moral arguments to prove something false and/or harmful, without understand the true workings of reality, or caring about them. But the problem is that they are wrong, not being motivated by morality. Being motivated by morality is good, almost axiomatically so. I am motivated by morality. My goals of technical, logistical and economical efficiency are motivated by morality. I see efficiency itself as a form of morality (or maybe morality as a form of efficiency. But that gets into semantics).