Abstract
Recently, alternatives to both the structure and content of ‘orthodox’ just war theory have been proposed by Jeff McMahan and David Rodin. In this paper, I draw on this debate to show that key ideas in just war theory can be disputed in both of these respects. More broadly, it is unclear how we should assess the debate between differing conceptions of individual principles (such as just cause and proportionality) and the competing wider theories in which they might be situated. I employ the idea of reflective equilibrium, taken from John Rawls, to show how these conflicting viewpoints might be understood and assessed. I argue, then, that contemporary just war theory faces both important questions of substance, and a set of difficult meta-theoretical issues concerning the grounds on which competing just war theories can be assessed. Futhermore, I contend, this should influence the character of – and our expectations for – real-world just war institutions.
Introduction
In the ongoing and shifting ‘war on terror’, just war theory – our body of resources for the moral assessment of war – has faced demands for extension and revision. Some of the most pressing and controversial questions of just war have indeed concerned the application of just war theory to contemporary conflicts, notably Iraq and Afghanistan. This paper, however, draws attention to a set of deeper disputes and disagreements within just war theory. In particular, one locus for such disputes has been the alternative account of just war generated by an analysis of the morality of self-defence, as in the works of Jeff McMahan and David Rodin.
In this paper, I use the backdrop of this dispute to interrogate some fundamental questions concerning just war theory. I argue that what might be taken as the apparent unity and determinacy of Just War Theory is, on closer examination, much less evident. That is, the central moral resources by which to judge war just or unjust are open to reasonable dispute in both their content and structure. Of course, just war theory is itself a diverse tradition, so this lack of determinacy might not be thought surprising. Certainly, we can speak of different and overlapping secular and religious traditions of just war, and the scope for cultural diversity and difference in ideas of just wars has been widely documented. 1 However, far from showing the breadth of diversity, such studies often point to a large degree of cultural or doctrinal overlap or convergence on central aspects of an idea of just war, such as necessity, just cause, and non-combatant immunity. 2
My point here is rather different; my investigation focuses on the modern western tradition, and in particular the content and structure of principles thought to be central to it. I aim to highlight a philosophical diversity in how these ideas can be interpreted and related. In this essay, I say something about how this diversity should be understood, its implications and how far it might be resolved. Now, almost all moral concepts admit of some dispute, or ‘grey areas’. Furthermore, when translated into real-world circumstances, they provoke further dispute over how law and politics should reflect (or shape) morality. However, the kinds of dispute and indeterminacy I highlight in this paper are neither peripheral, nor in this sense political. Instead they are central and philosophical, concerning how the moral agenda of just war theory should be understood, constituted, structured and evaluated.
The just war tradition offers an account of when war can be justly be undertaken (jus ad bellum) and how wars may be justly fought (jus in bello). In its ad bellum form as a limitation on the resort to war – which is my focus here – it is standardly thought to offer a number of moral principles that serve as criteria against which to test the justice of the resort to war. These criteria are:
just cause; rightful intention; legitimate authority; necessity or last resort; reasonable hope of success; proportionality; formal declaration of war.
Just war theory is widely understood and applied as being relatively fixed – composed of a well-established set of principles – and freestanding – independent of other issues of justice. 3 As a distinct historical tradition, 4 it predates, and can exist apart from, recent thinking on other questions in the political philosophy of international affairs – such as human rights, global distributive justice and political and moral cosmopolitanism. Just war thinking is a ‘two-thousand-year-old conversation about the legitimacy of war that has over time crystallised around several core principles’. 5 Especially compared to other putative ‘traditions’ such as liberalism, the central features of just war’s account of the resort to, and conduct of, war are often thought to be readily identifiable, as reflected in the list of principles. They also lie relatively close to current international law in at least some respects. 6 In examining the scope for dispute within just war theory, my analysis suggests that this picture is, to an extent, false. Just war theory is far from freestanding with respect to a wide and deep range of ethical questions. Nor are these core principles settled or, necessarily, fully coherent. The relation, then, between the moral and legal rules governing war is a complex one. Given the space available here, I cannot hope to provide a comprehensive and irresistible argument for this conclusion across all aspects of just war theory. Instead, I settle for illustrating my claims, and offering some considerations in support of them, in respect of a few central issues of just war.
This essay proceeds in three sections. In the first I briefly consider questions of the application of just war norms to particular cases. These are, I suggest, the questions most obviously raised concerning just war during the ‘war on terror’. However, I will focus here on a set of deeper theoretical disputes and issues within just war theory. The next section considers these questions, of the content and structure of just war. In particular, I examine the just war criteria of just cause and proportionality. I show how, in these two cases, central ideas of just war theory and their interrelation can be viewed in diverse and competing ways. The following section then aims to draw attention to issues of just war meta-theory – that is to say, of how to judge the validity, purpose and adequacy of just war theory, and thus how we might compare these competing just war theories. I will suggest that the ideas I address are, at best, difficult and under-examined: at worst, the problems posed might be genuinely intractable.
Application
One obvious class of disputes over just war theory concerns its application to particular cases. The evaluation of conflict from a just war perspective asks for an assessment of morally relevant factors, such as intent, proportionality, necessity, negligence. The context of the war on terror has posed precisely such questions – is the harm incurred by civilians in Afghanistan proportional? Was the putative presence of weapons of mass destruction in Iraq sufficient to yield a just cause for war? How can just war principles be applied to new weapons technologies, such as the use of unmanned drones? Partly, these are purely factual questions. They concern, for example, who committed the initial act of aggression, or what the likely consequences of a given course of action would be. Partly, also, these issues ask for an assessment of practices in the war on terror from a just war perspective. These are issues, it seems to me, which admit of some dispute, but not the kind of dispute that might be thought to undermine just war theory – they are salient precisely because just war theory is being used to assess the conflict at hand.
Of course, just war theory in the age of the war on terror has been tested. The war on terror has prompted demands for ‘new rules’ to fit this ‘new war’, and it is quite possible for the application of the theory to show up serious deficiencies and limitations. 7 The shifting nature of violence, and technological change in the means by which that violence is done, might provide reason not merely to extend or apply but revise just war theory. Analysis of the application of just war theory to the ‘war on terror’ might lead us, in its radical extreme, to the conclusion that just war is not suited to the contemporary world. To my mind, however, such a conclusion would be faulty. Just war theory, I take it, represents our best moral analysis of the use of violence. 8 Regardless of the forms violence takes, or the context it occurs in, we might expect the fundamental moral logic to remain the same. Whilst war has changed, it has also stayed the same, at least in its basic morality. From this view, any discordance would illustrate the particular immorality of contemporary violence rather than the weakness of just war theory.
None of this, of course, denies that resolving these questions of application might generate some difficult issues, in particular where fine-grained judgements need to be made in order to ascertain the justice of the war. Furthermore, an examination of real-world cases can yield reflection on the nature of just war theory in a way that would prompt the same kind of theorizing I will do here. Equally, though, a focus on narrow questions of how to apply just war theory should not come at the cost of obscuring genuine and deep difficulties in the very nature of a just war theory.
Theory
A second area of dispute, then, concerns the content and structure of just war theory itself. Notably, prominent contemporary accounts of the justified use of force stress a smaller, more tightly connected nexus of considerations, rather than the six or seven discrete principles at the core of traditional just war thinking. For example, Jeff McMahan’s account centres on linked notions of liability, proportionality and necessity. 9 David Rodin’s twin accounts of ‘liability’ and ‘lesser evil’ killing are ultimately accounts of proportionality alone. Though they allow for 13 different variables to enter the relevant calculation, both “are, at root, rich forms of the proportionality relationship between a substantially shared set of underlying normative factors”. 10 Understanding the relationship of such accounts to just war theory, I submit, requires us to assess both the content and structure of just war. In respect of its content, the investigative focus of McMahan’s work in particular, on how key ideas of proportionality and just cause should be understood, has illuminated the problems at the core of formulating these demands. With regard to the structure, McMahan and Rodin’s accounts shrink a principled account of just war into a less pluralistic form. In ‘orthodox’ just war, the criteria of jus ad bellum reflect discrete moral demands, and each must be satisfied in turn. On Rodin’s account in particular, this is radically altered: all relevant factors are instead to be assessed, and potentially traded off against each other, within a single calculus. In this section, I examine (briefly) the content of two central just war criteria – just cause and proportionality – and the relationship between them, to demonstrate the difficulties involved in assessing these most basic components of just war theory.
Just cause
In ‘standard’ jus ad bellum, the criterion of just cause demands the presence of a reason strong enough to justify the resort to war. Perhaps more so than other criteria, just cause has been thought to be fundamental to the overall justice of war. Notably, without a just cause, it would seem impossible for a war to be proportionate since there would be no relevant good for the evils of war to be weighed against, and the criterion of just cause also plays a key role in determining against whom force may be used. Just war theorists have presented and considered a range of potential just causes for war, but the form and substance of the idea have not always been thoroughly unpacked. From this perspective, Jeff McMahan’s work represents an important step. In a persuasive account of the just cause condition, McMahan argues that just cause can be approached through determining the kind of wrong which would justify killing and maiming. He writes:
There is just cause for war when one group of people – often a state, but possibly a nation or other organized collective – is morally responsible for action that threatens to wrong or has already wronged other people in certain ways, and that makes the perpetrators liable to military attack as a means of preventing the threatened wrong or redressing or correcting the wrong that has already been done.
11
I take the key task, then, for a test of just cause, to be to provide an account of wrongs that might be thought to be of the appropriate kind and seriousness to warrant the resort to war. To do so, McMahan suggests, ‘we can, in particular, consult our beliefs – which are quite robust and stable – about which kinds of wrong are sufficiently serious that the killing or maiming of the perpetrator could be justified if it were necessary to prevent or correct the wrong’. 12
As a methodology to give content to the idea of just cause, the appeal to intuitions prompts further questions. It would require us to engage with and critically appraise our intuitions, so as to determine which were sufficient robust and stable to ground such an account. Where our intuitions were internally conflicted, the resulting account of just war might well be incoherent, or reflect differences on key moral questions. I address some of these issues in the next section. Notably, on a range of issues, it may be that our intuitions are far from settled or robust – certainly, recent just war theorizing has suggested revisions that can appear strongly counter-intuitive. Thus, McMahan’s own work suggests that moral responsibility for a wrong is sufficient to ground liability for killing and maiming, even when this responsibility lies with a civilian population. 13 Work by Fabre and Øverland has argued that the poverty inflicted by rich countries on poor ones is a ground for war: Robyn Eckersley has suggested that killing can be justified as a response to certain serious environmental harms, on grounds beyond their impact on human life. 14 Though self-defence, at least, might be thought to represent an intuitively settled just cause, it still needs to be determined which rights (if we deploy the language of rights here) warrant the use of lethal force in their defence.
The internal logic of such an account also admits of problems. For example, McMahan explicitly disallows a number of small harms from being summed so as to generate a harm sufficient to yield a just cause for war. 15 The reason for such an approach appears strong: small slights, no matter how great in number, should not justify killing. However, conceptually, large harms are often small ones writ large. While it might seem that a war to reclaim a kilometre of territory would lack just cause, it is equally apparent that a war to reclaim several thousand kilometres is one to redress the same kind of harm, though in a different quantity. It is not clear how, with respect to harm, considerations of magnitude and number map onto kind and seriousness.
Structurally, we can note that, if the test of just cause takes something like this form, just cause is not a criterion that can be given content alone. Instead, it is already deeply connected to other principles familiar to the just war tradition, since something like McMahan’s formulation explicitly invokes notions of necessity and proportionality. It supposes the necessity of harming those liable to avert the wrong, and demands a relationship of proportionality between the purpose of the violence (the kind and seriousness of wrong to be righted) and the harm to which the person liable would be exposed. Just cause on such an account is itself a proportionality calculation: it asks what kind of wrong is serious enough to make killing or maiming the perpetrator the right response. This is a proportionality test which keeps one side of the balance constant – the killing or maiming of those potentially liable – and asks after the other side of the balance: what kind of wrong is bad enough to justify this harm? Put like this, an interrelationship between the central principles of jus ad bellum is present in the formulation of its most important principle. Not least, this prompts the question of how just cause is to be separated – if at all – from the principle of proportionality that also appears in just war thinking. 16
Proportionality
‘Classical’ proportionality, I take it, demands that ‘the destructiveness of war must not be out of proportion to the relevant good the war will do’. 17 Similarly, McMahan’s notion of wide proportionality, as outlined in his recent book Killing in War, tracks the wider destruction of war, demanding proportionality of the ‘harm inflicted on those who were not liable to any harm at all’. 18
To understand the content of a calculation of proportionality, we need to know which harms, and what goods achieved or preserved, should count in a proportionality relationship, and how heavily they should weigh. McMahan, in ‘Just Cause for War’, stipulates that only benefits and wrongs that reach the level of just cause should be included. 19 In his influential account, Thomas Hurka maintains something similar: only goods (or the aversion of evils) of the level of just causes can count in a proportionality calculation. 20 However, in a footnote in Killing in War, McMahan has since withdrawn his stipulation, and does not appear to replace it with another. The narrow proportionality calculation present in the principle of just cause – concerned with violence done to the perpetrators of wrongs – retains, and indeed expresses, this requirement: only serious evils are weighed. 21 But if I read McMahan correctly, in a calculation of wide proportionality, we count any ‘good effects that can weigh against and cancel out the bad effects of the war’. 22 It might be tempting to place different restrictions on the good and bad effects of war: thus, Hurka allows for all bad effects, but only a certain kind of good effect, to be weighed. The effect of such a restriction, I take it, is to make our theory of war more or less restrictive. The fewer good effects can be counted, the less likely that a war will be proportional, ceteris paribus. It is unclear, as I will discuss, whether the larger aim of achieving a more restrictive theory of war is the right kind of reason in itself to discount certain good effects. Furthermore, the distinction between generating a good effect and preventing a bad one seems to draw its force from combining the rather different contrasts between actions and omissions, and harming and failing to benefit. Here, I set aside the task of providing an unproblematic account of generating and preventing good versus bad effects, and continue to discuss the relevance of both goods and evils.
We can place accounts of the level of good and harm to be considered in jus ad bellum proportionality on a continuum between two extremes. At one extreme, a maximally wide account of such good and bad effects is to make the test of proportionality in war one of justifying the ‘all things considered’ lesser evil. That is to say, all consequences are weighed up and assessed as good, bad, or neutral. At the other end of the spectrum is a view which maintains that only a very limited range of goods and evils – those which in themselves are of the kind and seriousness of harm or good to yield just cause for war – can contribute to the satisfaction of the proportionality requirement.
There are good reasons to be cautious about each of these extremes – reasons grounded in what we want an account of just war in general (and proportionality in particular), to do. The broadest category of goods and evils would include trivial good and bad effects, and allow enough trivial effects to outweigh much more important goods and evils. Also, there will be some goods and evils which we do not want to count. That a group of people are clamouring for war, and only happy when they get one, or that a war might benefit us via the long-term prevention of potential future aggression, are precisely the kinds of pressures towards war that just war theory, in its practical incarnation, is designed to be a bulwark against. The broadest model of inclusion, then, might be too broad: instead, we are looking for a more moralized and restrictive account.
On the other hand, restricting proportionality only to factors of the kind and seriousness that can constitute just causes is also problematic. This standard seems too insensitive to the significant damage to relevant interests (for example, environmental degradation, disruption to civilian life) that might fall short of yielding a just cause for war, or for the possibilities for a just war to do relevant further good that would offset some of its evils. Furthermore, proportionality in ‘classical’ just war theory should function as a restriction on the resort to war even when the requirement of just cause is met. Setting the bar for the proportionality calculation at the same level as that of just cause merely duplicates the just cause criterion. Thus, a structural reason exists for proportionality to do a different body of work, or else just cause might be absorbed into it – as perhaps McMahan’s and Rodin’s approaches go some way to suggesting.
Thomas Hurka’s response to this problem illustrates these difficulties with the content of the proportionality test. He proposes that only harms reaching the level of a just cause should count, but immediately acknowledges that the threshold for just causes which should count for a proportionality calculation is lower than those sufficient just causes for war: instead, they can be ‘contributing’ just causes.
23
Worryingly, Hurka acknowledges that there is little systematic basis for distinguishing between these two kinds of just cause. He writes:
… this raises the question whether there is some unifying feature that gives these contributing causes their status. So far as I can see, there is not; like the sufficient just causes, they are just the items on a list. But there are intuitive limits on what can go on this list.
24
As with McMahan’s account of just cause, we are thrown back on our intuitions about the seriousness we attach to particular harms and goods. In particular, we might be troubled that, if the relevant weightings of moral harms are ‘just the items on a list’, our account of proportionality runs the risk of being ad hoc.
Like just cause, we can inquire into the place of proportionality within the structure of just war. If we adopt a strong test for the factors that matter to proportionality – so that only those which reach the level of a putative just cause could count in such a calculation – proportionality and just cause, to a large extent, will perform the same moral task for a theory of just warfare. As in Rodin’s account, we are pushed towards a view on which everything is factored, with various weightings, into a single proportionality account. Our account of how just war theory ought to be structured and interrelated should, I take it, reflect two kinds of demand. First, general demands of theory-building, such as parsimony: a just war theory would be less adequate, all things considered, if it contained more criteria than it needed to, in order to specify the dimensions of justice in war. Relatedly, it should be clear how criteria relate to each other, and the how the moral ‘labour’ is to be divided amongst them. But second, also, the design of a theory reflects an assessment of the relevant moral demands, of the aims that guide the theory. As one famous example, the relationship between Rawls’s principles of justice is one way in which the moral content of this idea of justice finds expression. 25 Similarly, I take it that just war theory should be structured in a way consonant with, and expressive of, the key moral commitments and overall aim of the theory. It is to these questions of the deep purpose and nature of just war theory that I now turn.
Meta-theory
In the previous section, I outlined how the basic nature of two key just war principles, and the relationship between them, are not settled questions. This is not to deny that just cause and proportionality, and other central principles of just war theory, are widely affirmed. But if the content and interrelationship between principles can vary on different interpretations of the values and their organization, we need to enquire into the foundations of a just war account. What should guide our decisions amongst competing interpretations and organizations of these values? This involves asking after the grounds on which a just war theory should be constructed and judged, issues of what I hesitantly term just war meta-theory.
To illustrate the difficulties surrounding these issues, we can usefully compare the meta-theories of war employed by perhaps the two most prominent contemporary thinkers of war: Michael Walzer and Jeff McMahan. Of course, some have argued that, because McMahan’s theory of war is revisionist or unorthodox, it should not be assessed against traditional just war theory. For my purposes here, though, this begs the relevant question, that of the basis for determining whether or not McMahan’s theory counts as a ‘just war’ theory at all. 26
Walzer’s account of just war begins ‘midstream’, finding the morality of war in ‘the moral arguments that everywhere accompany the practice of war’. 27 He aims to interpret the morality of war through critical reflection on the way people think about war: ‘reiterated over time, our arguments and judgments shape what I want to call the moral reality of war – that is, all those experiences of which moral language is descriptive or within which is it necessarily employed … the moral reality of war is not fixed by the actual activities of soldiers, but by the opinions of mankind’. 28 This approach to morality of war, of course, reflects Walzer’s more general moral method, that moral philosophy is a matter of interpretation rather than discovery. 29 Of the structure and content of his just war theory – which roughly mirrors the ‘orthodox’ sketch with which I began this paper – Walzer writes ‘we have made it so, not arbitrarily, but for good reasons. It reflects our understanding of states and soldiers, the protagonists of war, and of combat.’ 30 For Walzer, one relevant consideration in reflecting on morality is the law of war. Walzer aims to articulate and take account of a full range of ‘articulated norms, customs, professional codes, legal precepts, religious and philosophical principles, and reciprocal arrangements that shape our judgments of military conduct’. 31
McMahan’s approach is, at first sight, very different. His is an enquiry into what he terms the deep or objective morality of war. Unlike Walzer, who sees his exercise as interpretative, for McMahan, ‘the morality of war is not a product of our devising. It is not manipulable; it is what it is.’ 32 McMahan, then, views the philosophy of war as an exercise in, if not discovery, at least something more than interpretation. The starting point for this enquiry is an account of individual self-defence: war, McMahan affirms, differs from self-defence only in scale. 33 The relationship with the law of war is another central difference in both content and method between the two theorists. For Walzer, as I have noted, our legal conventions are bound up with, and help us to generate, the morality of war: there is a conjunction between the morality and law of war. 34 McMahan, by contrast, holds that there may well be a strong disjunction between the two. McMahan argues that, given humanity’s current circumstances, the law of war should not necessarily reflect the moral reality: the laws of war should be designed instrumentally ‘to bring about outcomes that are more rather than less just or morally desirable’. 35 As an example of this strategy, McMahan argues that, as a matter of morality, some morally responsible non-combatants are properly liable to direct and intentional force. 36 That is to say, targeting such civilians is wholly consistent with the moral rules of war, rather than a regrettable violation, which might be justified in rare and desperate circumstances (as Walzer holds). Nevertheless, considerations, including a concern for abuse of these moral principles, should lead us to maintain an absolute legal prohibition on the intentional killing of non-combatants in war despite this messier moral reality. 37
This strategy of disjunction between the morality and law of war prompts interesting questions that I cannot address here – for example, the impact of the division on combatants’ motivation to uphold the law of war, how the punishment of morally justified lawbreakers should be approached and the kind of world in which this disjunction might not be necessary. 38 More importantly for my purposes here, McMahan suggests that confusion between the law and morality of war can lead theorists and commentators to cling to accounts of war which – as a claim about the morality of war – are false. If this were true as an explanation of Walzer’s theory, it might easily be shown that McMahan’s perspective is superior. However, such a charge is not clearly successful. That legal and moral restrictions on war developed in tandem does not show that the moral restrictions did not come first: the legal conventions may reflect deep moral convictions and relevant concerns about how war is to be restricted in the real world. Nor is it clear that the question of ‘which came first’ should matter. While it is surely true that some origins for moral judgements – for example, bias or excessive self-interest – clearly invalidate the moral views that result, a consideration of relevant legal rules shaped by experience of war does not seem to fall into this kind of category: instead, our experience of the operation of the law of war, it might be contended, should properly influence our view on related moral questions.
A further contrast lies in the basic presuppositions of these two theories. On Walzer’s theory, the aim explicitly is to restrict resort to war: war is always a wrong, and is only to be resorted to reluctantly as the lesser of two evils. 39 McMahan’s position, as an investigation of the deep moral logic of war, holds that the killing of those liable to be killed is no evil. As McMahan writes: ‘wars in the narrow sense are therefore not always great moral evils and it is not always true that the best response to such wars is prevention. Just wars, for example, ought seldom, if ever, to be prevented.’ 40
In the picture I have sketched, these two approaches offer very different accounts of how we might understand and test a just war theory, and what we might test it against. But simultaneously, both approaches have something in common. Orthodox just war theory, as in Walzer’s formulation, invokes and expresses our considered intuitions in moral argument about war, and McMahan, too, is committed to the salience of our moral intuitions on war. Thus, throughout Killing in War, our considered judgements or first thoughts serve as test or support for aspects of McMahan’s theory, as I highlighted in respect of just cause. 41 McMahan concedes that our considered intuitions on war matter: intuitions are deployed to test or confirm arguments concerning war. 42 I do not want to maintain that there is anything improper in this: this paper, at various points, has attempted something like this exercise. But such an approach prompts questions about how to judge its validity or success, since it is also a clear intention of McMahan’s theory to call some of these intuitions into question, including – importantly – ones concerning the importance of threat and responsibility as foundations for legitimate targeting. On what basis should we determine which considered judgements should be reshaped, and which should form the argument for, or test of, our approach?
Given the role of our considered intuitions or judgements in these two accounts of just war, my suggestion here is that we view this and related questions in the light of John Rawls’s idea of reflective equilibrium. 43 Reflective equilibrium, as a methodology in moral philosophy, demands coherence between our considered judgements and our theory of justice – to apply it to this case, our theory of just war. On such a model, it is not the case that our considered intuitions are the final court of appeal: it is not merely the role of moral theory to systematize and extend them. On the other hand, nor is the validity of moral theory independent of our intuitions about the matter at hand. Instead, we move back and forth between our intuitions and theories, adjusting both until a relation of mutual support exists between them. 44 We do not merely systematize our intuitions – as Norman Daniels puts it, ‘since such opinions are often the result of self-interest, self-deception, historical and cultural accident, hidden class bias, and so on, just systematising some of them hardly seems a promising way to provide justification for them or for the principles that order them’. 45 Thus, considered judgements are open to revision. Nevertheless, on Daniels’s account, we also treat them as provisional ‘fixed points’ from which to reject alternative moral conceptions: he writes, ‘we are not inclined to give up certain considered moral judgements unless an overwhelmingly better alternative moral conception is available and substantial dissatisfaction with our own conception at other points leads us to do so’. 46 Something like Daniels’s account of the role of considered judgements might find expression in both McMahan’s and Walzer’s approaches.
An examination of reflective equilibrium focuses our attention on a range of questions concerning just war meta-theory. Of course, viewing the dispute between Walzer and McMahan in such a context does not itself settle anything, though I think it is helpful in two important respects. First, the process of wide reflective equilibrium – Rawls’s preferred variant – asks that other theoretical resources, including additional moral and non-moral theories, are brought to bear on impasses and ambiguities. As one example of this, just war theory as an account of the kind and seriousness of wrong which might justify the loss, suspension, or overriding of an individual’s rights has close links to an account of human rights more generally. In particular, the question of the kind and seriousness of wrong which constitutes a just cause, and how different costs and benefits of war could be assessed, might be rendered more tractable if assessed by standards of human rights. These could yield, in a systematic way that Hurka could not, the kinds of factors that would be morally relevant in an assessment of proportionality. However, I would not wish to suggest that an appeal to human rights wholly settles these questions. Human rights – their justification, extent and content – are themselves not self-justifying, but instead the summary of a complex body of further moral theorizing.
Which other moral and non-moral facts and theories should be brought to bear will shape the resulting theory of war in distinctive ways. From the standpoint of wide reflective equilibrium, then, just war theory is far from freestanding: instead, it must be deeply connected to other wider moral and non-moral theories and judgements, including the morality of self-defence, but also issues in international political philosophy, notably accounts of global justice. While the content of global justice might help to underpin and generate a list of just causes, the institutions of global justice would be relevant for accounts of both legitimate authority and the availability of alternatives to the ‘last resort’ of war. One especially important (moral and non-moral) issue will be that of whether war comprises a set of circumstances so distinctive that special moral rules apply. 47 Furthermore, the philosophy of war would reflect – and reflect back upon in turn – our accounts of moral responsibility and excuse, and the distinction between acts and omissions (to highlight but two more general moral questions). 48
Second, reflective equilibrium offers an account – or rather two accounts – of how competing theories can be assessed against each other. On some interpretations of reflective equilibrium, where competing equilibria emerge, one can be shown to be maximally coherent. That is, it coheres in the right way with the largest expanse of relevant facts and moral and non-moral theories. 49 It might be thought that in a similar way one account – and only one account – of just war theory could be maximally correct. Two considerations might caution against such a position. First, the search for a single maximally coherent account of war might place too much weight on the idea of coherence. A number of competing theories can recognize the general value of coherence or mutual support in theory-building, but the more it was employed to make fine-grained judgements about the objective superiority of one or another theory, the more its authority might be questioned. The structural value of coherence is neutral as to the content of the theories, and so might be thought vulnerable to being ‘trumped’ by the more substantive values contained within them. While a rough and ready account of what it means for a morality to cohere is, I assume here, fairly accessible and relatively robust, judging maximal coherence might put a weight on the methodology that it cannot bear. Second, at the very least, the ultimate triumph of one particular account of just war theory seems distant: it would require the kind of further philosophical investigation which just war theory has only begun to attract. Indeed, it indicates that an agenda of meta-theoretical inquiry in just war theory must run alongside – and through – the study of more substantive issues.
An alternative account of reflective equilibrium would allow for the possibility of multiple coherent, but different, theories of just war. Each of these would present a unified set of judgements and theories that cohered in turn with a wider array of background moral and non-moral theories. Adjudicating between these conceptions might prove difficult or impossible, given the foundational issues at stake. Might something like Walzer’s and McMahan’s contrasting accounts of the nature and purpose of just war theory, suitably expanded and filled out, be contrasting but coherent accounts? Many of the moral judgements about the justifiability of violence are present in both kinds of theory – for example, the ideas of proportionality and the idea that violence can only be justified to avert a wrong. However, this leaves open, as in my sketch of these two accounts, different ways of understanding and formalizing these requirements. Not least, as I have shown, much hangs on the division of labour between principles and the overall shape and aim of a theory of war.
Instituting the application of just war theory
I have shown that an assessment of just war theory rests on a series of deep theoretical and meta-theoretical issues that will, at best, resist easy resolution: at worst they may be wholly intractable. Recently, Jeff McMahan has outlined a proposal for an international just war ‘court’ – which might take a binding or non-binding form – to issue authoritative guidance on the justice of war. In particular the target of such a proposal is unjust combatants’ ignorance of the injustice of their cause, and the difficulties involved in judgements concerning the facts and likely consequences which bear on the justice of war. The institution, I take it, aims to address epistemic problems concerning the application of just war theory to particular wars, the kind of issues I have already discussed briefly. As McMahan writes: ‘the main purpose of an ad bellum court would be to provide authoritative guidance about whether wars in the narrow sense are just or unjust. Its judgments would be addressed not only to states and their governments, but also to soldiers and citizens.’ 50
McMahan is careful to defend his proposal against critiques of political naivety. His proposal can perhaps be read as an attempt to provide a particular account of the just war principle of legitimate authority, or at least as an effort to render some authorities legitimate. My account of the kinds of uncertainties and disputes within just war theory suggests a further set of problems, though. It is unclear how such a body would – or could – resolve the disagreements and indeterminacies in the content of just war theory, not least because resolving these would seem to require deciding how competing versions of the content and structure of just war theory should be assessed against each other. Seen from this angle, the effectiveness of such an international body might well be severely limited. If the judgements of the body should, effectively, be conditional or hypothetical imperatives that acknowledged the indeterminacy of just war principles in a wider context of competing considerations, then the effectiveness of the court as a way of generating epistemic certainty that a war is just or unjust would be sharply limited.
McMahan notes that conflicting votes amongst the judges might measure ‘moral uncertainty’. 51 The more intractable these disagreements within just war theory are, the more that we should expect reasonable conflict between the votes of the judges, though this will not, strictly, express uncertainty: the judges themselves might well be very certain in their differing verdicts, reflecting their particular weighting and balancing of morally relevant considerations. 52 Conflict amongst the judges measures the extent to which experts reasoning in good faith, and analysing the same material, could reach different verdicts. The more that there are marked lines of divergence amongst just war experts, of course, the more there may be a case for the just war court being composed of a diverse range of theorists representing different theoretical perspectives, or even for reshaping the remit of the court. The extent and character of the disputes over the content of just war theory, then, might influence the shape the institution should take, and would also guide the kind of verdict that the court should issue. 53
Conclusion
In this essay, I have argued that there is scope for indeterminacy not merely in how just war theory is applied, but in its constituent parts and the relationship between them – indeed, there is deep disagreement as to the very purpose of the theory. To highlight the scope for diverse accounts of just war theory, and to stress the need for a wider, meta-theorical context for just war theorizing, is not to argue that just war theory is uniquely problematic in either of these respects. It would be unsurprising, for example, if close examinations of moral issues such as punishment, humanitarian intervention or the character of cosmopolitan political institutions revealed a similar level of ambiguity and contestation. On the kind of account of reflective equilibrium I have offered here, just war cannot claim a unique body of meta-theory – instead, wider bodies of moral and non-moral theory shape many different areas of thought. Whether war has a unique nature that generates a special morality is an issue, in itself, that has prompted disagreement between theorists. Nevertheless, competing views might agree that that war comprises an especially difficult and pressing set of moral and practical issues.
It might be that the issues I have highlighted are ultimately tractable: that given sufficient critical engagement from a wide array of moral philosophers, citizens, leaders and soldiers, the meta-theory of just war and its substance can be fixed in a way that compels rational assent. Of course, this might involve a substantial reformulation of just war – even a rejection of the tradition, and a revolution in the way we think about war. Theorists taking such an approach may well be critical of my analysis: it might be charged that I find dispute where there is only error on the side of one or another party. As a diagnosis of issues within the content and structure of just war theory, though, I hope that this paper will be viewed as a contribution to just such an exercise in truth-seeking. A contrasting set of critics might take my analysis to show that just war theory is hopelessly confused, and so must be jettisoned. But we live in times when it would be irresponsible of leaders, citizens and soldiers not to engage in the moral assessment of war. I think such a move would be unwise and, in a deep sense, immoral and impossible: just war theory, after all, should reflect nothing more (or less) than our best account of how war should be judged. An alternative approach, though, is to survey the difficulties I have raised and perceive instead the need for just war theory to provide an account of how far these deep differences, and their consequences, must be managed, respected and accommodated. It may be that this exercise would yield a distinctive theory – and indeed meta-theory – of just war.