This neglect would be less troubling if necessity were either immediately perspicuous, or peripheral to the ethics of self-defence. Unfortunately, closer examination proves the simple, pretheoretical account of necessity to be inadequate. And if defensive harm can be justified only if it is necessary, this constraint could hardly be more important. Nor is this only a problem in self-defence: necessity plays a crucial role in both popular and philosophical thinking about the ethics of war. We standardly think that regardless of whether the other criteria for permissible harm in war are met, unless force is necessary to avert an unjustified threat, we should refrain from action.[5] Indeed, for one prominent school of just war theorists, necessity underpins the principle of noncombatant immunity, perhaps the single most important moral constraint on the use of force in war. These philosophers think that permissible killing in war is identical to permissible killing in self- and other-defence, indeed, that justified wars reduce to a collocation of justified acts of self- and other-defence. They argue that, even if the other conditions that would make noncombatants legitimate targets of lethal force were satisfied, since killing noncombatants will never satisfy the necessity constraint, they are immune from attack on those grounds alone.^[6]

The necessity constraint, then, is at the heart of the ethics of both self-defence and war, and yet we know little about it. This paper seeks to remedy that defect. It proceeds in two stages: first, an analysis of the concept of necessity in self-defence; second, an application of this analysis to the ethics of war, looking both at its implications for the reductionist school of just war theory, and its application in the laws of war.

Extract from the conclusion:

The revisionist critique of conventional just war theory has undoubtedly scored some important victories. Walzer’s elegantly unified defense of combatant legal equality and noncombatant immunity has been seriously undermined. This critical success has not, however, been matched by positive arguments, which when applied to the messy reality of war would deprive states and soldiers of the permission to fight wars that are plausibly thought to be justified. The appeal to law that is sought to resolve this objection by casting it as a practical concern, a pragmatic worry about implementation, which while germane to debates over the laws of war, need not undermine our convictions in the fundamental principles the revisionists advocate. This response is inadequate. Revisionists have not shown that soldiers should obey the laws of war, in practice, when they conflict with their other moral reasons – our worries about application remain intact. Moreover, a theory of war that offers only an account of the laws of war, and a set of fundamental principles developed in abstraction from feasibility constraints, is radically incomplete. We need to know how to apply those fundamental principles, and whether, when applied, they lead to defensible conclusions. Only two options seem to remain. Perhaps the revisionists’ arguments for their chosen fundamental principles are sufficiently compelling that we should stick with them, and accept their troubling conclusions – in other words, accept pacifism. Alternatively, we need to revise our fundamental principles, so that when applied they yield conclusions that we can more confidently endorse.

Though it does not save the revisionist view from the responsibility dilemma and cognate objections, the appeal to law does raise an important, and previously inadequately theorized, question – or, rather, resurrects a neglected topic, discussed in depth by historical just war theorists such as Grotius and Vattel. There are good grounds for distinguishing the laws of war from the morality of war, and for adjusting the former to accommodate predictable noncompliance, that should not impact on our account of the latter. Nonetheless, I have argued that there are some profound moral insights underlying both combatant legal equality and noncombatant immunity: specifically, we cannot infer from a combatant’s side having not satisfied jus ad bellum that he may not justifiably use lethal force; and other things equal, it is more wrongful to harm a nonliable noncombatant than to harm a nonliable combatant.

The principle of distinction between combatants and noncombatants holds that warring parties must distinguish between the two groups and intentionally attack only the former.[1] Although catastrophically abused during the twentieth century, it remains the most important limit on how we fight. It draws support from most ages, and most cultures,[2] is central to the laws of war,^[3] and is almost unanimously endorsed by national governments, international institutions, and global civil society.[4] Moreover, this theoretical consensus has often influenced military practice, at least among liberal democracies. The city-busting tactics of the recent past are now deprecated, replaced by an almost exclusively counterforce approach.^[5] Even contemporary just war theory has few critics of noncombatant immunity—indeed, some regard it as ‘a sort of touchstone of moral and intellectual health’.^[6]

And yet, despite this near-universal endorsement, recent theoretical developments have left the principle of distinction embarrassingly difficult to justify. In the canonical text of contemporary just war theory, Michael Walzer’s Just and Unjust Wars, the argument was simple: all combatants lose their right to life because they threaten others’ lives; all noncombatants, by definition non-threatening, retain that right.^[7] But recent work has seriously undermined this account of how we lose the right to life, showing that justified and unjustified combatants should not enjoy equal permissions to non-consensually harm one another.^[8] Merely posing a threat is not sufficient to lose one’s right to life: the threat must be unjustified. Moreover, nor is posing an unjustified threat necessary for liability: a politician who culpably sends others to fight unjustifiably might be liable, despite posing no threats himself. Walzer’s revisionist critics conclude that liability is grounded in (1) responsibility for (2) contributing to (3) threats of unjustified harm.[9]

This responsibility-based view resonates strongly with familiar intuitions about the use of force in self- and other-defense, and has received compelling theoretical support from its advocates.[10] And yet, when applied to the practice of war, it seems incapable of sustaining our most familiar moral commitments. In particular, if individual responsibility is what matters, then contrary to the principle of distinction many noncombatants will be liable to be killed. As much as 25 percent of the population of industrialized countries works in war-related industries;[11] many of the rest of us foster public support for our state’s military enterprises; we provide the belligerents with crucial financial and other services; we support and sustain the soldiers who do the fighting; we pay our taxes and in democracies we vote, providing the economic and political resources without which war would be impossible. If individual responsibility for the threats posed by our state is what matters for liability, then few of us will be immune.

Unwilling to accept the radical implications of their views, a number of revisionist just war theorists have recently argued that we can ground wartime liability in responsibility, without putting noncombatant immunity under threat. Although they pursue different strategies to this end,[12] one in particular has achieved a remarkable degree of consensus. The argument is simple: acts of war are not permitted unless they are necessary; targeting noncombatants is (almost never necessary); so targeting noncombatants is (almost) never permissible.^[13] This seductively simple argument has also attracted Walzer’s contemporary defenders, who reject the individualism of the responsibility-based view. Contractarian and rule-consequentialist theorists of war have appealed to the same argument in a subtly different way: the principle of distinction, they argue, reduces the suffering of war without ever denying belligerents a necessary means to success.[14]

In such a disputatious field as just war theory, this consensus is striking. Equally surprising, however, is the paucity of theoretical and empirical enquiry into this consensus. Although it seems to demand a careful analysis of precisely what necessity means in this context, as well as some evidentiary support for its plainly empirical central thesis, this argument’s advocates instead reason a priori, as though the concept were immediately perspicuous, and their descriptive claims self-evidently true. In this paper, I try to redress this complacency. I start with a brief analysis of the necessity constraint on the use of force, before turning to the empirical question. My aspirations are both substantive and methodological: to test the necessity-based justification for the principle of distinction, and to argue that just war theorists must support their empirical claims with appropriate evidence.

The stakes are high. If the principle of distinction can be grounded in necessity alone, then there is no need for a deeper justification for this fundamental moral limit, conversely if the necessity-based argument fails, then the search for that deeper justification must continue.

Here’s the introduction:

The burgeoning literature on jus post bellum has repeatedly reaffirmed three positions that strike me as deeply implausible: that in the aftermath of wars, compensation should be a priority; that we should likewise prioritize punishing political leaders and war criminals even in the absence of legitimate multilateral institutions; and that when states justifiably launch armed humanitarian interventions, they become responsible for reconstructing the states into which they have intervened – the so called “Pottery Barn” dictum, “You break it, you own it.” Against these common positions, this chapter argues that compensation should be subordinate to reconstruction, with resources going where they are most needed and can do the most good, rather than to the most aggrieved. Just punishment, meanwhile, presupposes just multilateral institutions – the victor cannot be trusted to mete out punishment fairly. And just interveners, who have already taken on such a heavy burden, are entitled to expect the international community to contribute to reconstruction after they have made the first and vital steps. After presenting each of these objections in greater depth, the chapter proceeds to draw some tentative inferences from the threads running through each, and suggest that they illustrate a distinctive flaw in the way in which jus post bellum is addressed by many just war theorists, who not only see the war as the grounds of post bellum duties, but also take it to specify their content: Specifically, they take the rights violations with which wars are imbued to be the basis for post-war action, but take the content of post-war duties to be focused on rectifying those rights violations, rather than the more forward-looking goal of establishing a lasting peace. This backward-looking orientation unduly confines these theorists to making attributions of fault, to a limited palette of normative concepts, and to a focus on the belligerents rather than the international community as a whole. Undoubtedly warfare creates a distinctive normative relationship between belligerent states (though we must question how much of this devolves to the citizens of those states). War does generate grounds for post-war duties – but there are other grounds for those duties too, moreover the grounds should not determine the content. It of course matters that the citizens of two states harmed one another in violation of their rights. But when the war is done, peacebuilding should be the priority, not raking over the wrongs of both sides. Sections 2–4 present the objections, Section 5 offers the tentative analysis and proposes a shift in focus toward an ethics of peacebuilding, and Section 6 concludes.

***UPDATE***

Turns out Mother and Baby did get through! So I’ll have two pictures at the exhibition, and in the March edition of Wanderlust. It’s the Destinations Holiday & Travel Show (3-6 February 2011) at Earls Court, and then at Birmingham NEC from March 4-6. Here’s the picture

Cecile Fabre is co-editing the collection with me, and we have a very exciting roster of contributors, offering a range of different perspectives on the justification of national defence. The basic problem will be set up by papers by myself (derived from this one) and Patrick Emerton and Toby Handfield, while David Rodin will explore the legacy of and response to War and Self-Defense. Defences of the individualist view will come from Jeff McMahan and Cecile Fabre. Alternative approaches will be represented by Chris Kutz (looking at democracy and just cause), Yitzhak Benbaji (offering a contractarian alternative), Annie Stilz (focusing on national defence through the lens of territorial rights), and Margaret Moore (writing from a liberal nationalist perspective). This is an extremely exciting project, and we’re very much looking forward to taking it to fruition. We anticipate submitting a manuscript for consideration in mid-February 2012.

Wars are large-scale conflicts between organised groups of belligerents, which involve suffering, devastation and brutality unlike almost anything else in human experience. Whatever one’s other beliefs about morality, all should agree that the horrors of war are all but unconscionable, and that warfare can be justified only if we have some compelling account of what is worth fighting for, which can justify contributing, as individuals and as groups, to this calamitous endeavour.

Although this question should obviously be central to both philosophical and political discussion about war, it is at the forefront of neither. In recent years, philosophical discussion of warfare has bloomed, but the debate has focused on whom we may kill, on the assumption that our aims are justified.[1] Political debate, meanwhile, is more concerned with matters of prudence, international law, and public justification, than with reassessing what is worth fighting for.[2]

For wars of intervention to halt or prevent massive humanitarian crises, this gap is not so troubling. When warfare is the only means to prevent the mass killing or enslavement of the innocent, the purposes of military force are clear enough (though undoubtedly many other problems remain).[3] The problem is more pressing, however, for the justification of national defence.[4] Although commonsense morality and international law view national defence as the paradigm case of justified warfare, grounding this consensus is surprisingly difficult.[5] We typically believe that any state is justified in using lethal force to protect its territory against any form of uninvited military incursion by any other state. And yet we lack a good argument to explain why this should be so.

In this chapter, I explain why one familiar and otherwise plausible approach to the justification of killing in war cannot adequately ground commonsense views of permissible national defence.[6] Reductionists believe that justified warfare reduces to an aggregation of acts that are justified under ordinary principles of interpersonal morality.[7] The standard form of reductionism focuses on the principles governing killing in ordinary life, specifically those that justify intentional killing in self- and other-defence, and unintended but foreseen (for short, collateral) killing as a lesser evil. Justified warfare, on this view, is no more than the coextension of multiple acts justified under these two principles.

Reductionism is the default philosophical approach to thinking through the ethics of killing in war. It makes perfect sense to ask what principles govern permissible killing in general, before applying them to the particular context of war. If it cannot deliver a plausible set of conclusions about when national defence is permitted, then we must either revise our beliefs about which conclusions count as plausible, or else face the significant challenge of developing a different theoretical model for justifying warfare—an exceptionalist model, which views war as an exception to the regular moral landscape, to which principles apply which apply to nothing else but war.[8] We must show, in other words, that there is something worth fighting for in wars of national defence, which is not engaged when we use force in any other context.

The chapter proceeds as follows. Section II sets out the argument against reductionism.[9] Section III considers and rebuts one common response to the argument, which has often been thought sufficient grounds to disregard its conclusion. Section IV then asks whether a modified reductionism would survive unscathed by the argument. Finally, section V sets out some desiderata on a plausible exceptionalist alternative. Section VI concludes.

You can see the paper here: A Liberal Defence of (Some) Duties to Compatriots.