Differences Between War and Torture
The differences between war and torture are morally relevant, but JMR wants to make them absolutist, and I don't think they form a difference of kind, just a difference of degree enough to raise the standards for when torture might be allowable compared to when fighting in war might be allowable. In both cases, the action is to serve some further end, and keep in mind that being a soldier is not the same as making a decision to go to war, which is premeditated in a way that merely fighting in war at the command of a superior officer is not. If the decision to go to war is ever ok, then we can't say that torture is wrong for being premeditated (and the same goes for capital punishment, which is certainly premeditated killing).
It seems to me that the differences between war and torture are these:
1. War gives people a fighting chance, while torture is implemented once people are captured. This is a morally important difference. We should be much more reluctant to treat people badly when they can't resist than we should be when they have a hope of escape. But we still might have superior firepower and be able to surround people in war, where they don't have very much of a fighting chance, and that doesn't necessarily make it immoral to cause them harm. It might give us less reason to try to kill them, but if harming them is necessary to capture them or prevent them from fighting further, then we will often do so. The goal is prevention of fighting, though, not harm. With torture, therefore, to be analogous, it must be with a goal to prevent future fighting. But isn't it? So this at most seems like a difference of degree, not of kind.
2. War can involve indiscriminate killing but is usually focused on enemy combatants rather than civilians, and ideally efforts are made to minimize collateral damage. This feature actually favors torture over war, because torture is at least carried out against only those deemed to be enemies. (Mistakes might be made about that, but mistakes can be made in war too, so that's not a difference.) It seems, then, that this difference actually makes torture less bad in this one respect than making the decision to go to war is in this one respect.
3. There's a much more immediate goal with war. You want to stop military resistance for the sake of peace, and you fight against those resist. Or you want to stop an invader from doing harmful things, so you fight the actual invader. With torture, you want to stop people from doing bad things, but your torture someone who has been rendered harmless to prevent someone else from doing harm. It's thus indirect. If the person is totally innocent, that provides a strong reason to resist torturing. But if the person is involved in the evil activity, even if now harmless, that undermines part of the argument in the case where it's an innocent who would be tortured. It strikes me that this isn't an in-principle argument against torture, at least in the case of the non-innocent, because the immediate/non-immediate barrier has already been crossed in many cases with war. For example, going to war to defeat soldiers of Japan or Germany in WWII to stop Hitler is already indirect in some sense, even if it's also directly stopping the people being used as tools of Hitler. If we take out the Taliban to stop al Qaeda, even if the Taliban are perpetrators of evil, it seems there's an indirect motivation, and that doesn't seem to be an illegitimate motivation. The presence of a direct one helps justify the act, but is it absolutely necessary, or does it just raise the standard of proof for justifying the indirect act? I think the latter.
The Narrowness of My Conclusion
I'm not arguing that torture is the correct moral act in any actual case. It may, for all I've said, be so rare that it's never happened and never will. Or it may, for all I've said, be a lot more common and actually practiced by the United States in cases where it's morally allowed. There's certainly a strong moral consideration against it, and there may be all manner of practical obstacles to ensuring that it could be done in ways that have a chance of being morally allowable. It's not something that should be seen as intrinsically good, but then neither is war. For someone who accepts the Christian gospel, there may even be more reasons to resist doing anything even close to torture.
But I'm not saying there are no reasons not to torture, and I'm not taking a stance on the practical issues of how and when it might ever be morally allowed. I'm not trying to defend any particular policy that condones or prohibits torture. I'm not commenting on whether any particular interrogation method counts as torture or whether a certain set of restrictions should be enough to ensure that it's done in a moral way. What I'm saying is that the arguments against torture are either implausible or non-absolutist, whereas JMR is claiming that he has absolutist arguments against torture. I haven't seen one that succeeds among all the arguments he's given. They all seem to me to allow for some at-least-possible cases of doing it, or else they make claims that go beyond the shared assumptions we have or ones that I'd be willing to grant.
Are We Really Disagreeing, Though?
But then I think it's also worth noting JMR's definition of torture, given in a comment on one of the posts: "For the purpose of this discussion, I am describing torture as the desire to "break the will" of a man and to inflict permanent psychological and physical harm."
If that's what torture is, then I'm not sure anyone currently defending torture is defending that. Not many defenders of extreme interrogation methods see the mere goal of breaking someone's will or the infliction of psychological or physical harm as an end worth pursuing in its own right. Some might see breaking someone's will as a means to an end, but the torture anyone is defending isn't itself the desire to break people's wills or to inflict permanent or psychological harm. I suppose there are those who approve of such things as mere revenge, and I would oppose that as fully as JMR does. But that's not what's at issue in the public debate over these matters. That makes me wonder if I'm not really disagreeing with JMR, since what he calls torture isn't what I'm saying might sometimes be allowed.