1. Proportionality in International Humanitarian Law

Proportionality, in general terms, is a legal principle used to assess the legality of measures that one may pursue to further or accomplish a proper purpose. The principle may operate in a variety of ways. It may seek to establish, first, qualitative relations between that end and the means used. Under German law and, under its influence, European law, proportionality is deemed to exist only when the means used are capable of producing the legitimate end pursued. Secondly, the principle may seek to establish quantitative relations between a permissible end sought and the means employed to achieve it. Thus, the means may exceed what that end requires or yield adverse effects that are not necessary to attain the legitimate goal. Thirdly, as developed by German courts in the interwar period, the principle may also require that the means themselves be adequate in light of other community goals.Footnote ¹

At present, international humanitarian law (IHL) proportionality analyses seem concerned mostly with quantitative relations. Article 51(5)(b) of the 1977 Additional Protocol I thus considers as ‘indiscriminate’ attacks those ‘which may be expected to cause incidental loss of civilian life, injury to civilians, damage to civilian objects, or a combination thereof, which would be excessive in relation to the concrete and direct military advantage anticipated’.Footnote ² The variety of proportionality standards developed in other legal systems may contain some promise of expanded doctrinal breadth for the principle of proportionality in IHL.

The focus in this article, however, stems from the observation that, under all three tests, the end in question must be legitimate. Stated critically, we can say that resort to the principle in concrete cases presupposes that the end is legitimate, that the purpose is proper. This article, then, is an exploratory deconstruction of ‘legitimate ends’ presupposed in IHL proportionality analyses.

IHL provisions utilise proportionality analyses – of the second, quantitative type – in a variety of areas: from targeting;Footnote ³ through the limitation of the effects of weapons on soldiers and the environment;Footnote ⁴ to gradations in ‘measures of control’ to be taken against civilian protected persons.Footnote ⁵ Similarly, the principle limits the power of the occupant to requisition foodstuffs, civilian hospitals, and the like.Footnote ⁶ Not surprisingly, then, commentators often assert that proportionality is a general principle of IHL, which governs – that is, restrains – other aspects of the conduct of war even where this is not explicitly or implicitly provided for.Footnote ⁷ Whether or not proportionality is an overarching principle in IHL, my concern here is with the nexus it affects between restraint and legitimate end.

The first part of the article, then, addresses the proper purposes, or goals, that are referenced by IHL whenever recourse is made to proportionality analyses (Section 2). Next, I seek to identify the content of legitimacy of goals in IHL proportionality analyses. This takes place against the backdrop of the traditional aversion, in IHL doctrine, to questions of legitimacy. That aversion, grounded in the jus in bello/jus ad bellum distinction, implies the existence of legitimate ends jus in bello that are independent from legitimate ends associated with the legality of use of force, jus ad bellum (Section 3). Section 4, however, demonstrates that IHL has traditionally been predicated on the accommodation of military reason: it permits such means as are instrumental to the end of weakening the military forces of the enemy. This rests, I suggest, on a construction of war as an instrument of politics. To explore this foundational assumption of IHL doctrine, I turn to the author of that construction of war in Section 5: the Clausewitzian construction of war as an instrument of politics suggests, contrary to orthodox assertions of IHL doctrine, the existence of an ineluctable nexus between jus in bello means and jus ad bellum ends. Jus in bello derives, in other words, from ad bellum legitimacy. IHL proportionality and military necessity analyses, inevitably, do address jus ad bellum legitimacy. Section 6 critically explores some of the implications of Clausewitzian war theory for IHL doctrine, goals and operational strategy. Section 7 suggests that these implications compel a conceptual reassessment of IHL base assumptions and doctrinal assertions, its limits and aspirations, its achievement and its costs. The conclusion recaps the principal findings and assertions made in the article.

2. Proper Purpose: ‘Military Necessity’

On one level, an answer to this question can be sought in the particular rule requiring proportionality analysis. Thus, rules on targeting reference the legitimacy of making military objectives the ‘object of attack’. The prohibition on weapons causing ‘superfluous injury and unnecessary suffering’ references the legitimacy of neutralising enemy combatants. Measures of control against protected persons are predicated on the legitimate security concerns of the state in whose territory enemy nationals are present; or, in occupied territory, the security concerns of the occupant and the legitimate interests it has in maintaining its control of the occupied territory for the duration of the war. Rules limiting the requisition of humanitarian supplies recognise the legitimate sustenance requirements of the occupying forces.

What specific proportionality provisions identify as proper purpose is not arbitrary. Rather, these provisions embody the application of systemic reason in specific problem areas. What these provisions recognise as proper purposes, or legitimate ends, is subsumed under the single heading of ‘military necessity’. Whenever IHL utilises proportionality analysis, it references some form of recognised, legitimate military necessity. We can say that, through military necessity, proportionality indicates legitimate ends in bello.

Yet the systemic reasoning of military necessity and the legitimacy of ends in bello itself rest on prior assumptions constructing the nature of war. Implicit in contemporary proportionality analyses, in other words, is a concrete construct of the war phenomenon and, based on that construct, the strategies law employs to restrain war. To appraise proportionality and its restraining qualities, then, we need to inquire into the military necessity logic and its underlying assumptions; how law constructs war would tell us what purposes and ends are legitimised by military necessity – and why. First, however, we need to consider how contemporary legal doctrine constructs legitimacy in bello.

3. Legitimacy in IHL: An Antinomy?

Here we come to an apparent antinomy. Proportionality, through necessity, references legitimate ends; yet IHL doctrine expresses a principled aversion to inquiries into propriety of purpose, justifiability of motives or legitimacy of ends.Footnote ⁸ Under prevalent doctrine, these are matters regulated by the law governing the legality of the use of force (jus ad bellum), not the law dealing with the manner in which force is used (jus in bello). In the language of the Preamble to Additional Protocol I, IHL applies and is to be interpreted ‘without any adverse distinction based on the nature or origin of the armed conflict or on the causes espoused by or attributed to the Parties to the conflict’.Footnote ⁹

Since necessity and proportionality analyses of the manner in which force is used reference, by their nature, legitimate ends, we must assume that they address legitimate ends that are different from those referenced by rules governing the legality of the use of force. Jus in bello legitimacy and jus ad bellum legitimacy are, in other words, disparate matters. This resolves the apparent antinomy: IHL is averse to the jus ad bellum legitimacy, yet it employs its own independent legitimacy analyses.

This raises the need to identify the content of jus in bello legitimacy; this would allow us to test the assumption that it is truly distinct and independent from jus ad bellum legitimacy. Before this inquiry can begin, we must note that shying away from adjudicating, or even commenting on, the legitimacy of ends jus ad bellum is more than an incidental idiosyncrasy of IHL doctrine, lawyers and institutions. Rather, abstention from questions concerning ‘the nature or origin of the armed conflict or … [its] causes’ is central to explanations of IHL's goals, characteristics and operational strategy. The total separation of jus ad bellum and jus in bello, and the legitimacy test each utilises, is theorised as a sine qua non for the effectiveness and the very existence of rules restraining war conduct.Footnote ¹⁰

4. The Codification of Military Reason

Today, the accommodation of military reason is often implicit in IHL norms. Historically, however, military reason was codified in explicit terms in early IHL instruments as the intellectual premise of restraining war through law.Footnote ²⁵ One of the fullest elaborations of military reason as an overarching, foundational legal principle appears in the Preamble to the St Petersburg Declaration of 1868, which ought to be quoted here in full:

These few paragraphs raise some fascinating questions concerning the foundational assumptions of the modern project to humanise war through law that are, alas, rarely discussed in the literature.Footnote ²⁷ Our immediate concern is the military reason this text expresses.

This text, rather than having ‘revolutionized military thinking’,Footnote ²⁸ militarised the laws of war. It modernised the law of war by making military reason its conceptual stepping stone. The Preamble to the St Petersburg Declaration seems to offer a clear and narrow answer to the question ‘what ends are legitimate in bello?’: weakening ‘the military forces of the enemy’ and, to this end, using means (and methods) ‘sufficient to disable the greatest possible number of men’. And, couched in military terms, the legal precepts of necessity and proportionality to which the text refers are rooted in military logic itself. As we shall soon see, it is not that the formula of the St Petersburg Declaration ‘has become a classic definition of the purpose of war’;Footnote ²⁹ rather, that formula codified a pre-existing construction of war and its purposes.Footnote ³⁰ Moreover, the standard of legitimacy in bello in the St Petersburg Declaration, though it casts this formula in military terms, proceeds on the basis of two assumptions that, in 1868, required no explication. One was that the pursuit of war itself was legitimate and necessary: the Covenant of the League of Nations,Footnote ³¹ the Kellogg-Briand PactFootnote ³² and the UN Charter were decades into the future. The other assumption involved a construction of war itself. Thus, the proposition that weakening ‘the military forces of the enemy’ was a legitimate object in war – indeed, was the only legitimate object in war – rested on the understanding that war was an instrument of politics. Formulated by Clausewitz several decades before it was codified in the St Petersburg Declaration, the instrumental construction of war suggests an ineluctable nexus between jus in bello and jus ad bellum legitimacy.

5. The Clausewitzian War

The reason why weakening the military forces of the enemy could be considered the only legitimate objective in war was that modern war – ‘war between civilized nations’, in the St Petersburg Preamble – was fought for ends that transcend the military dimension of war. This was the construction of war propounded by Carl von Clausewitz (1780–1831) in On War (1832) – immediately before the formative period of the modern law of war. For Clausewitz, a first-hand witness of the Revolutionary and Napoleonic Wars, war was instrumental to ends that were political.Footnote ³³

I am not suggesting here that a specific war needs to have a specific cause, nor any kind of a just war theory. Rather, I refer to the reason for what Clausewitz called ‘pure’ war – that is, the ideal of war as a theoretical postulate, divorced from its specific political purpose and circumstances. (‘Real’ war, in contrast, is modified from abstract theory by extraneous circumstances, conditions and uncertainty).Footnote ³⁴ I refer equally to the application of reason to war. War, Clausewitz posited, was neither science nor art;Footnote ³⁵ yet beyond the structural uncertainties it created, it was subordinated to reason. As such, it was also amenable to legal regulation. This was precisely the analytical point of departure of the drafters of the St Petersburg Declaration and other architects of the modern law of war.

In the Clausewitzian universe, the reason of war both ‘pure’ and ‘real’ is not military; waging war, or weakening the military forces of the enemy, are means to ends, not ends unto themselves. Rather, the successful conduct of war was its service to ends that lie beyond the military sphere. Military success – of the kind discussed in the preamble to the St Petersburg Declaration – in and of itself does not represent victory. Victory consists of one side imposing its will – that is, its political war aims – on the other through the application of force.Footnote ³⁶ The Clausewitzian war is an ‘act of force to compel our enemy to do our will’, and the Clausewitzian victory, though attained by military means, occupies the political realm: it constitutes ‘success in compelling the enemy to do our will’.Footnote ³⁷ Thus, the object of pure war is to overcome and disarm the enemy: the armed forces must be destroyed or incapacitated; ‘The Country must be occupied’ to prevent the raising of ‘fresh military forces’ (or, presumably, other war-making capabilities); and the enemy's will must be broken. War can come to conclusion only when ‘the enemy government and its allies have … been driven to ask for peace, or the population made to submit’.Footnote ³⁸ Political coercion brought by military means is the essence of victory: the imposition of the victor's war aims on the vanquished.

In Clausewitzian war theory, the military and the political are inseparable. War is instrumental to political ends – a political instrument, a means to a political end: ‘not merely an act of policy but a true political instrument, a continuation of political intercourse, carried on with other means’.Footnote ³⁹ This is the modern war reason: wars are fought to political ends; conduct in war must serve the political ends of war. Political ends, then, control the choice of military means and govern the conduct of belligerents in bello, even if the inherent uncertainty of war and other factors drive the antagonists towards escalation.Footnote ⁴⁰

In postulating that ‘the only legitimate object which States should endeavour to accomplish during war is to weaken the military forces of the enemy’, and that ‘for this purpose it is sufficient to disable the greatest possible number of men’, the authors of the St Petersburg Declaration adopted the Clausewitzian construction of war and its implications: that the military means would serve political ends; that the former drew their legitimacy from their instrumentality to, and the legitimacy of, the latter; and that the two spheres, the military and the political, are inseparable. Ends jus in bello ultimately depend on ends ad bellum.

Incidentally or not, the innate nexus between jus ad bellum and jus in bello legitimacy is illustrated in the Clausewitzian treatment of questions of proportionality, or ‘The Scale of the Military Objective and of the Effort to be Made’ in the title of Chapter 3.B of the eighth book of On War. Here, Clausewitz discusses the ‘degree of force that must be used against the enemy’ which largely (but not exclusively) ‘depends on the scale of political demands on either side’.Footnote ⁴¹ Thus, the application of force ‘should be suitable and proportionate to the military objective and the political purpose’.Footnote ⁴² Other factors may intervene to modify the Clausewitzian requirements of proportionality: uncertainty that is inherent in the ‘size and variety of factors to be weighed’ in war, its ‘tendency toward the extreme’ and the acts of the adversary may all compel greater force.Footnote ⁴³ Conversely, constrained resources and domestic concerns may inhibit against maximum efforts.Footnote ⁴⁴ Yet intervening factors do not severe that nexus: they merely cause a belligerent to be ‘driven to adopt a middle course … using no greater force, and setting … no greater military aim, than would be sufficient for the achievement of his political purpose’.Footnote ⁴⁵ Yet decisions on the extent of force to be used, even before the impact on civilians is factored in, do hinge on political purpose.

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That is not to say that Clausewitz advocated a legal principle of proportionality. He was not concerned with normative legitimacy of the kind that lawyers address jus ad bellum or jus in bello. Rather, he sought to systematically ‘explore the ultimate nature and dynamic of war’, demonstrating in the process that war was amenable to reason.Footnote ⁴⁶ Still, his observations on the reason of war, the instrumental nexus between ends and means as between the political and the military spheres, were highly influential in the formation of the modern law of war. It is noteworthy that he made these very observations, at the beginning of On War, precisely at the point where he excluded from consideration the legal aspect of war:

And so, the antinomy is far from being resolved. The Clausewitzian construction of war suggests that legitimacy jus in bello is not independent of legitimacy jus ad bellum. In the conduct of belligerents, military ends are instrumental to political ends; legitimate ends jus in bello draw on jus ad bellum ends. Proportionality and military necessity therefore must address ‘the nature or origin of the armed conflict or on the causes espoused by or attributed to the parties to the conflict’, contrary to contemporary doctrinal assertions. That was self-evident to the drafters of the St Petersburg Declaration; it was equally evident for Francis Lieber, who, in another foundational IHL instrument, asserted the instrumental nature of war and the consequent nexus between war's means and its ends. Article 68 of the Lieber Code, promulgated a few years before 1868, thus stated:

6. Implications of The Clausewitzian War Theory

War has changed since the time of Clausewitz. But while the means of war and the types of goal for which war is fought have been transformed,Footnote ⁴⁹ the essential nature of war has not: it remains a military means to political ends.Footnote ⁵⁰ What has changed is not the construction of war on which the modern law of war was predicated, but rather the normative environment. In other words, it is the first assumption made by the drafters of the St Petersburg Declaration that is no longer correct. The pursuit of war – the use of force between states – is now outlawed, subject to the familiar exceptions of self-defence or enforcement action by the UN Security Council. Other than those, war can no longer be considered legitimate and necessary. Outlawing war, however, did not change its fundamentally political character.

Proportionality analyses and the concept of military necessity itself address the means of war; orthodox IHL doctrine entrenches a complete separation of means and ends, decoupling the military from the political. The Clausewitzian construction of war suggests, however, that since ‘[t]he political object is the goal’ and ‘war is the means of reaching it, … means can never be considered in isolation from their purpose’.Footnote ⁵¹ If legitimate military ends derive from political ends in ‘pure’ war (and albeit to a lesser extent in ‘real’ war), than at the analytical level, legitimating the military means necessarily legitimates political ends. The origins, nature and causes of a conflict govern the conduct of the belligerents pursuing an efficient, rational war. The choice of military means in war is directed at creating conditions that are conducive to the imposition of one's political will on the enemy. A recent US Field Manual thus defines ‘landpower’ as

The Field Manual proceeds to discuss means, such as destruction of key assets and territorial occupation, which make the enemy ‘unable to resist the imposition of US will’, as well as the connection of causes, means and outcomes.Footnote ⁵³

The normative transformation brought about by the United Nations Charter makes suspect the assertion that the legitimacy of means and ends can be separated. Clausewitz tells us that the military and the political are inseparable. The goals of IHL may be humanitarian, but if war and the manner of its conduct derive from and are instrumental to the political sphere, IHL cannot be said to be politically neutral. Recourse to military necessity and proportionality presupposes the legitimacy of the war aims of the belligerents in question whatever their normative valence, for example, under the United Nations Charter. Suspending judgment about the legitimacy of such war aims operates, in practice, to validate them. Such recourse presupposes in equal measure the permissibility of one state imposing its will, by force or otherwise, on another. In other words, the question at hand is not merely whether the belligerent in question made lawful recourse to war; it concerns equally the permissibility of the political outcome sought by that belligerent. Imposing post-war arrangements on one's opponent by recourse to force amounts, under the Charter, to prohibited intervention which interferes with the right of ‘people of all States to administer their own affairs and determine their own political, economic and social system without external interference or control’.Footnote ⁵⁴ If the end is impermissible, the legality of the means used to bring it about is at least dubious. Weakening ‘the military forces of the enemy’ and disabling ‘the greatest possible number of men’, in the language of the St Petersburg Declaration, are not stand-alone ends; rather, they are means to imposing political war aims. In this respect, IHL legitimises all war aims – ‘the causes espoused by or attributed to the Parties to the conflict’ – contrary to the common doctrinal assertion.Footnote ⁵⁵ Whether such legitimisation is nonetheless warranted on other grounds is another matter; this I address shortly.

The instrumental understanding of war underscores the permissive aspect of necessity and proportionality. We tend to focus on the restraining effect of such principles, yet fundamentally they effect licence; the point of departure of both principles is the acceptance not only of the necessities of war but also acceptance that war itself may be necessary. Such acceptance cannot be easily reconciled with the UN Charter or, at times, with human rights law. It is true that today, IHL presents a number of absolute prohibitions (torture, or the taking of civilians hostage); yet most forms of protection it grants are relative, and susceptible to dilution by necessity and proportionality analyses. Humanity in war, in other words, remains largely subordinate to the necessities of war, to the war aims of the belligerents, and to the political sphere.

That the regulation of war legitimises war is not a new critique of IHL. It took strategic form in the preparation of the First Geneva Convention. Thus, the appeal made by Gustave Moynier in 1863, cited above,Footnote ⁵⁶ in defence of the charitable alleviation of ‘human passions and their deadly consequences’ was made in response to Peace Movement ‘detractors’ arguing that the introduction of humanitarian restraint into war ‘is legitimising warfare as a necessary evil’. Tolstoy made a similar argument, couched in moral, perhaps even utilitarian terms, in War and Peace.Footnote ⁵⁷ What Clausewitz tells us on the nature of war and the nexus between military means and political ends gives this critique a concrete normative form.

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This analysis of the principles of proportionality and necessity suggests that the distinction between jus in bello and jus ad bellum rests on shaky analytical ground: military means in bello draw their legitimacy from their instrumentality to, and the legitimacy of, political ends ad bellum.Footnote ⁵⁸ The Clausewitzian construction of war calls into question the assertions of IHL doctrine about its goals, characteristics and operational strategy. After all, IHL doctrine assumes that it can only exist outside politics. Jean Pictet, as Vice President of the ICRC, professed that just like that body IHL's ‘only chance of success lies in its being carried on, as far as possible, outside the sphere of politics’.Footnote ⁵⁹ To that end, doctrine constructs distinctions between the military and the humanitarian, on the one hand, and the political on the other. It casts the military sphere itself as apolitical: incidental to victory, not an instrument thereof; and if the military is apolitical (necessity is military, not political), it may leave room for humanitarian law, sentiment and action that, being politically neutral, do not jeopardise military victory. As such, compliance with humanitarian restraints can be made to appear a wise, cost-effective policy choice. Yet the first assumption made by the drafters of the St Petersburg Declaration is no longer correct:Footnote ⁶⁰ war has been now outlawed. Its pursuit can no longer be assumed to be legitimate and necessary. With this normative transformation, the political neutrality of IHL is no longer analytically sustainable.

IHL doctrine operates by decoupling military reason from political reason, and limits itself to accommodating the former. It is political, not military, legitimacy that the law avoids: the origins, nature and causes of the conflict vis-à-vis the parties to the conflict, not how these translate into military goals and policies. Military necessity is imagined as referencing only the military legitimacy of the military goals of war: IHL operates by permitting what is militarily necessary. Military necessity is distinct, and divorced, from political necessity. If compliance with humanitarian restraints is constructed as incidental to military goals (that is, as not jeopardising victory), military goals are themselves constructed as incidental to political goals.

The instrumental understanding of war suggests that such constructions are flawed. Clausewitz suggests that there can be no gap for the humanitarian between the military and the political spheres; these cannot be decoupled. Means and ends are inseparable, and so are assessments of their legitimacy. Pictet observed that IHL's only chance of success lies in its operation outside the sphere of politics; what can we read into the observation that IHL necessarily references and legitimises the war aims of belligerents, and that these are political par excellence? Other than critical reflection about legal doctrine (does it describe the reality of how IHL operates or does it, in fact, obfuscate that reality?), this mandates a reassessment of IHL's record and the feasibility of its strategy.

7. Final Thoughts: Coming to Terms with the Clausewitzian War

In the final analysis, the Clausewitzian construction of war suggests that IHL, through recourse to necessity and proportionality analyses, references not merely proper purpose in bello but also propriety ad bellum. Applying necessity and proportionality serves to demarcate an illegitimate sphere of conduct in war. At the same time, such exercise reaffirms not only a legitimate sphere of conduct but also, by refraining from commenting on the legitimacy of the ends of war, the legitimacy of conducting war in the first place.

Two principal imperatives emerge. The first impels a re-examining of IHL doctrine describing and constructing the relations between the humanitarian and the political. Clausewitzian military theory provides the impetus and powerful analytical tools for a conceptual reassessment of orthodox claims about IHL, its goals, its idiosyncratic characteristics and operational strategies. Other theoretical perspectives may provide equally important insight for such inquiries: in this respect, deconstruction of the IHL culture and how it impacts upon legal construction offers some promise. Legal doctrine emphasises modesty, pragmatism, realism, objectivity, independence and neutrality as markers of the law; cultural analysis may provide some clues to these markers (how come, one may ask, the mere proposition that law may legitimise war produces such a strong reaction in us?).Footnote ⁶¹

The other imperative is closely related. It concerns a critical evaluation of the law, its limits, its aspiration and its achievement. One implication of the Clausewitzian critique is that the common perception of IHL as independent (from the jus ad bellum), politically neutral and effect-objective is fictitious. The reasons why orthodox view considers these characteristics to be conditions precedent for IHL's ability to offer protection to victims of political violence themselves require exploration. Here the concern is not that the law constructs fictions; that, at this or that level, is the usual business of law. One question here is whether these fictions themselves serve a useful purpose; another question is whether the cost they exact is warranted. The answers may be positive, but the utility of these fictions must never be assumed.

With regard to costs, the Clausewitzian construction of war suggests that recognising military necessity indiscriminately (that is, available both to aggressor and defender) lends some legitimacy to causes and war aims that, under jus ad bellum, are illegitimate. Requiring that the requisition of foodstuffs in occupied territory be proportional to the resources of the country and the needs of the occupied territoryFootnote ⁶² thus permits the occupation army to feed off the land in furtherance of war policies that may well be in contravention of the United Nations Charter. Similarly, limiting the scope of permissible collateral damage to civilians is predicated not only on the permissibility of targeting military objectives but, more crucially, on the legitimacy of those political ends which attacks on such military targets seek to promote.Footnote ⁶³ Legitimising collateral damage caused in the pursuit of aggressive war legitimises, to some degree, its pursuit.

We turn, then, to the more difficult question of the useful purpose served by resorting to such fictions. Is the cost of legitimising illegitimate war acceptable? What other community goals does it serve? The answer offered by common wisdom (the same one professing the severability of means and ends) is that IHL's political neutrality is warranted for a combination of ‘practical, policy and humanitarian reasons’.Footnote ⁶⁴ These traditionally include the following arguments. First, it is argued that, notwithstanding the prohibition on the use of force, armed conflicts continue to occur and require moderation.Footnote ⁶⁵ Second, the indeterminacy and politicisation of jus ad bellum determinations, together with the rarity of Security Council designating the aggressor, is invoked in favour of employing indiscriminate standards of restraint applicable to all belligerents.Footnote ⁶⁶ Third, it is argued that distinguishing between belligerents on the basis of jus ad bellum criteria ‘would thus almost certainly lead to a total disregard for humanitarian law’.Footnote ⁶⁷ An associated argument is that placing a more onerous burden on aggressors would invariably cause them to fight without any restraints. Last, there are arguments about the moral equality of victims,Footnote ⁶⁸ and the individual protection objectives of IHL:Footnote ⁶⁹ victims should be protected irrespective of any wrongdoing by their state and its leaders.Footnote ⁷⁰

The analytical flaw identified in IHL doctrine does not necessarily compel the rejection of any of these arguments. It does, however, compel critical reflection on their persuasiveness and implications. None of these justifications for the equality of belligerents necessitates, for example, that IHL's point of departure should be the accommodation of licence. Analytically, the acceptance of all, some, or no permissible collateral damage at all – as long as such a standard binds all belligerents – is perfectly consistent with the fact that wars continue to occur and offers an equally pragmatic solution to the indeterminacy of jus ad bellum. The last of these hypothetical standards – under which no collateral damage is ever acceptable – would even inject moral content into the formal principle of the moral equality of victims.Footnote ⁷¹ It is at least uncertain, in other words, that the equality of belligerents really requires the cost of legitimising illegitimate wars: it can operate on the basis of censure as much as on the basis of licence.

At the same time, other considerations do warrant questioning whether the doctrinal fiction about the severability of ends and means really serves a useful purpose. Against the indeterminacy of jus ad bellum, it may be argued that the ‘unbounding’ of the Security Council since the end of the Cold War may facilitate the identification of aggressors and the appraisal of the legitimacy of the aims that belligerents seek to attain by force.Footnote ⁷² While the Council's practice in the past two decades or so still leaves much to be desired, we may be witnessing a shift towards greater jus ad bellum determinacy bolstered by an ex post facto exercise of jurisdiction by international criminal tribunals and the International Criminal Court.

The normative and institutional developments in international criminal law raise certain doubts not only with regard to the pragmatic argument about jus ad bellum indeterminacy, but also about the moral groundings of the doctrinal separation of means and ends. Why recognise, we may thus ask, the legitimate security concerns of, or any ratio of, civilian lives lost caused by the authors of wars fought for criminal purposes such as ethnic cleansing or genocide? Developments in international criminal law underscore the limits of persuasion; there may be moral points beyond which the end entirely vitiates the means employed to pursue it. To argue that the principle of equality of belligerents holds the authors of such criminal designs bound to a minimum standard of restraint, or that what would keep them from resorting to atrocities (which they are already committing) is the fact that the standards they are violating apply to all verges on the tragically nonsensical.

I am not suggesting that none of the justifications for separating means and ends ever holds water, or that we need to discard entirely the jus ad bellum/jus in bello distinction or the principles of necessity or proportionality. I am suggesting, however, that we can no longer assume – if we ever could – the correctness and propriety of the fictions employed by IHL doctrine. Reciting the common view, the prevalent understanding, about the goals of law, its characteristics, and how it operates does not encourage asking such questions. Orthodox doctrine, in the nature of orthodoxy, militates against innovative explorations. The answers it provides may be valid, but they require constant validation based on reason and evidence that rest on more than, and are external to, the assertions of orthodox doctrine.

Thus, we could find import in the fact that public opinion sometimes refuses to accept the verdict IHL has to offer on the acceptability of large-scale civilian casualties in attacks, campaigns and wars, as mandated by the rules. We could, rather than dismiss inexpert public opinion, find lessons in its insistence to infer from such unacceptable outcomes the unacceptability of the attack itself, the campaign or the war. If we are to take seriously our own claim that the law ought to draw from ‘the requirements of the public conscience’ – and include the public at large in that reference in the Martens ClauseFootnote ⁷³ – we may come to understand that public opinion is telling us, perhaps, that such ‘legal’ but inhumane outcomes are simply no longer good enough.Footnote ⁷⁴

It may be, to pursue another unorthodox line of exploration, that the irrelevance of the legitimacy of means to that of ends is no longer tenable, if it had ever been, and that the legitimacy of the decision to use force ought to be contingent, ex ante and ex post, on the manner in which that force is actually employed. Jus ad bellum legitimacy, perhaps, ought to be preconditioned to a significant degree on legitimacy jus in bello. Such a novel proposition, and others, deserves separate treatment, which I hope to pursue elsewhere.