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Law and Morality at War

Victor Tadros•

ROUGH DRAFT

A substantial body of recent work in just war theory claims that the moral

considerations that determine whether acts of individual combatants during a

war are permissible or wrong are not reflected in the laws of armed conflict

(the LOAC).1 Many also defend this divergence between law and morality. I

will offer a cautious case for revising the law to achieve greater convergence.

Let us call combatants fighting with a just cause ‘just combatants’, and

those fighting with an unjust cause ‘unjust combatants’. Let us call non-

combatants who support the just side ‘just non-combatants’ and those that

support the unjust side ‘unjust non-combatants’. I intend a capacious

conception of what it means to support a side – it might involve intending to

contribute to unjust threats, or doing so without intending to. By a ‘just cause’

• School of Law, University of Warwick. I am grateful to the Leverhulme

Trust for a Major Research Fellowship which allowed me to work on this

paper. I am grateful to Adil Haque and Andrew Williams for comments.

Apologies to Adil, who has a paper and a book with the same title. I didn’t

realize this until it was too late to change. 1 Jeff McMahan is the most influential proponent of this view. See, especially,

Killing in War (Oxford: OUP, 2009). His defence of the current divergence of

law and morality is set out most fully in ‘The Morality of War and the Law of

War’ in D Rodin and H Shue Just and Unjust Warriors: The Moral and Legal

Status of Soldiers (Oxford: OUP, 2007). For prominent accounts of the morality

of war with roughly similar implications, see, for example C Fabre

Cosmopolitan War (Oxford: OUP, 2012), H Frowe Defensive Killing (Oxford:

OUP, 2014).

2

I mean a cause that is sufficiently important to justify war, and thus

sufficiently important to justify intentional killing. Unjust causes include

everything from evil causes to good causes that are insufficiently important to

justify going to war.

I take my definition of a combatant from the LOAC. It includes both

members of the armed forces, and civilians who directly participate in

hostilities. The LOAC deems this group to be legitimate targets in war. They

do not clearly define what it means for participation in hostilities to be direct,

and military advice is often vague.2 I take the common view that whether

participation is sufficiently direct for the civilian to be a combatant, according

to the law, is a question of causal proximity.3

The International Committee of the Red Cross (ICRC) has published

non-binding interpretative guidelines on this issue, following a long

consultation with military lawyers, though their conclusions remain

controversial. It concludes that a person participates directly only if there is a

sufficiently close causal relation between the act and the resulting harm. They

suggest that this is so only if the harm in question is ‘brought about in one

2 See, for discussion, M N Schmitt ‘Deconstructing Direct Participation in

Hostilities’ (2010) 42 New York University Journal of International Law and

Politics 697, 705-9; E Crawford Identifying the Enemy: Civilian Participation in

Armed Conflict (Oxford: OUP, 2015) ch.3. 3 It is sometimes thought that direct participation also requires a mens rea

element of intent. See, for example, M N Schmitt ‘Humanitarian Law and

Direct Participation in Hostilities by Private Contractors or Civilian

Employees’ Expert Paper submitted to the International Committee of the Red

Cross October 2004, 15. Schmitt also thinks that causation must be ‘but for’,

but this is surely wrong – a person directly participates by loading bullets into

a gun, even if another person would have loaded the bullets had this person

not done so.

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causal step’.4 Although it is not clear how to individuate causal steps, this

idea seems so restrictive that it is not a plausible interpretation of the law, as it

would seem to exclude, for example, those who load weapons on the front

line, and the ICRC themselves recognize that these people directly participate

in hostilities.5 I take the proper interpretation to include these people.

The better view is that there is a threshold of causal proximity where a

person who crosses that threshold directly participates in hostilities. As it is

very hard to develop general principles of causal proximity,6 it is common to

rely on illustrative examples.7 The ICRC, for example, exclude those who

provide supplies and services, who finance the war, who are involved in

scientific research and design, and the production and transport of

equipment, unless this is included as an integral part of a specific military

operation designed directly to cause harm of an appropriate degree.8 Though

4 N Melzer Interpretative Guidance on the Notion of Direct Participation in

Hostilities (Gevena: ICRC, 2009) 53. 5 Ibid 66. See, also, Schmitt ‘Deconstructing Direct Participation in Hostilities’,

728. 6 For some of the problems, see H Beebee ‘Legal Responsibility and Scalar

Causation’ (2013) 4 Jurisprudence 102. 7 As do commentators. See, for example M N Schmitt ‘Humanitarian Law and

Direct Participation in Hostilities by Private Contractors or Civilian

Employees’ Expert Paper submitted to the International Committee of the Red

Cross October 2004 14-24; Y Dinstein The Conduct of Hostilities under the Law of

International Armed Conflict (Cambridge: CUP, 2016) 178-81. 8 Meltzer Interpretative Guidance on the Notion of Direct Participation in Hostilities

52-4.

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it remains contested, this seems plausible as an interpretation of the law as it

stands.9

I focus on the two most striking and familiar examples where the

LOAC and morality seem to diverge. First, the LOAC permit the killing of all

combatants, both just and unjust. But many philosophers claim that whereas

killing unjust combatants is often permissible, killing just combatants is often

morally wrong. Let us call the view that supports the LOAC as they stand

Legal Symmetry and the moral view Moral Asymmetry.

Second, the LOAC contain a strict and general prohibition on the

intentional killing of non-combatants, whether just or unjust. But many

believe that some unjust non-combatants are liable to be harmed or killed,

and so intentionally killing them is permissible if certain further conditions

are satisfied – for example that the killing is necessary to further a just cause

and is proportionate. There is disagreement about what makes non-

combatants morally liable, but the core case involves culpably making a

substantial contribution to lethal threats that are unjustly posed in war. Not

all people who do this directly participate in hostilities, and so many are

legally immune from attack. Let us call the view that supports the law as it

stands Strict Legal Immunity and the moral view Moral Non-Immunity. Of

course Moral Non-Immunity claims only that some unjust non-combatants are

liable to intentional attack.

Together, we can sum up these two divergences as follows. The

general distinction between combatants and non-combatants is legally

important. The LOAC permit intentional attacks on all combatants, and only

on combatants. But recent work in moral philosophy suggests that the law

does not cut at the moral joints: the general distinction between combatants

and non-combatants, as it is drawn by the LOAC, is morally unimportant.

9 See, also, D Akande ‘Clearing the Fog of War? The ICRC’s Interpretative

Guidance on Direct Participation in Hostilities’ (2010) 59 International and

Comparative Law Quarterly 180.

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What matters is whether one makes a substantial contribution to an unjust

lethal threat. Just combatants do not normally do this; some unjust non-

combatants do.

There are powerful arguments for Moral Asymmetry and Moral Non-

Immunity - I will briefly outline the most important. My main aim is to

evaluate the law in the light of these moral views. I will set out a case for

greater convergence between law and morality in both cases. As there are

difficult empirical questions, I make the case cautiously, and the case for

convergence on asymmetry is more powerful than that for convergence on

non-immunity.

I. Assessing the Laws of War

Before embarking on the particular laws that I focus on, let me respond to two

general concerns that Jeremy Waldron has recently expressed about

arguments that the laws of war should be revised. 10 First, the laws of war

have developed and been refined over generations, and are thus likely

suitable for governing war. Second, criticizing the laws of war will undermine

the fragile authority that they currently have without replacing them with

anything better, and will lead to more rather than less chaos. I respond to

these concerns in part because the general approach to the laws of war that

we find in academic scholarship, both amongst philosophers and lawyers, is

very conservative. Waldron’s ideas may explain the general trend.

In response to the first idea, it is not true that the laws of war as they

stand have stood the test of time. Many such laws are relatively recent

inventions. For example, the general rule regarding civilian immunity and the

exception for those who directly participate in hostilities was only clarified in

the second half of the twentieth century, following WWII, and it was codified

10 J Waldron ‘Deep Morality and the Laws of War’ in H Frowe and S Lazar

Oxford Handbook of Ethics of War (Oxford: OUP, forthcoming).

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as part of the Additional Protocols to the Geneva Convention only in 1977.11

They have received systematic judicial and academic critical scrutiny only

over the last two decades.

Prior to WWII, it was relatively common not to distinguish between

members of the armed forces and those who manufacture munitions.12 As we

have already seen, the proper interpretation of the direct participation

remains contested. The law is coming under increasing pressure when the

sources of significant threats are identified.

Furthermore, international institutions governing international

criminal law, most importantly the International Criminal Court (ICC), are

recent inventions. We should expect the development of these new

institutions to be accompanied by significant changes in substantive law over

time. Indeed, we are already seeing plenty of innovation by the ICC in

developing the scope of war crimes.13

The principle of equality of combatants has a longer history, and

Waldron might argue that we should be more confident in it. But the fact that

some set of laws has evolved over time, and gains significant consensus, is at

best weak evidence that the laws are good. There are many explanations for

the creation and persistence of bad laws: prevailing cultures may make them

seem attractive, they may serve powerful interests, changing the law may cost

a great deal of time and effort, the law may not have been carefully

scrutinised, no one may hold the levers of change, or there may be many

levers that need to be pulled, and the wrong people may hold these levers.

The fact that the laws of war develop through political consensus

should give us little confidence in them – they are likely to reflect the interests

11 For a brief history, see E Crawford Identifying the Enemy: Civilian

Participation in Armed Conflict (Oxford: OUP, 2015) ch.3. 12 See Ibid, 56. 13 For an overview, see W A Schabas An Introduction to the International

Criminal Court 4th Edn. (Cambridge: CUP, 2011).

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of powerful states and their political leaders, and they are likely to be

insensitive to changes in warfare, given that the mechanisms of change so

clumsy and inefficient. They are thus likely unsuitable for regulating current

wars, given changes in technology, changes in the ways wars are fought,

changes in the importance of the nation state and global pressures, and so

on.14

We cannot be certain whether the laws of war are performing well or

badly because we cannot know how events would have proceeded with

different laws. But we do have some evidence that the laws are no good.

Although the laws of war have developed over centuries, we have hardly

seen a decline in the destructive effects of war. Approximately 160 million

people died in wars in the twentieth century, and their destructive effects

were much greater. Recent conflicts in the Middle East hardly suggest that

things are getting better, despite rapid development of the law. It is, of course,

possible that had the laws of war been revised in ways that I will recommend

the devastation caused by war would have been even greater. But I see no

prima facie case for caution.

How about Waldron’s second idea: that moral critique of the laws of

war is dangerous, because it undermines the authority of existing laws

without achieving anything better. Those who recommend revising the laws

of war do recommend new laws. But it is possible that the hope for better

laws remains unrealized, and we are left with substandard laws with less

authority.

But the self-effacing attitude that Waldron recommends is itself

dangerous (as is recommending it). Laws gain authority when people think

they have a reason to accept them. They are more likely to think they have

14 The list of prohibited weapons is perhaps the most obvious example where

the interests of the powerful have resulted in perverse laws - antipersonnel

land mines are not banned (though parties contracting to the Ottowa

Convention 1997 agree not to use them), but poisoned arrows are!

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such a reason if they are held up to regular public scrutiny. The fact that the

laws of war have not been substantially revised since 1977 itself is treated by

some as evidence that the laws of war are obsolete, making them less likely to

comply.15

Furthermore, philosophers have a minimal direct impact on the law –

legal practitioners are also subjecting the laws of war to significant critical

scrutiny, and they are more likely to be directly influential. That is not to say

that philosophy is unimportant in shaping the law. But its influence is slow

and indirect. The aim of philosophical reflection on the law is to contribute to,

sustain and develop an intellectual culture of careful scrutiny, where

decisions of the military, politicians, legal practitioners, and lawmakers are

subject to serious and deep evaluation. This eventually contributes to the

broader political culture in which laws are developed, and where different

views are assessed and refined. It is reasonable to hope that this overall

enterprise will have a positive effect on the slow development of legal and

political institutions.

II. Moral Asymmetry

With this in mind, let us explore whether Moral Asymmetry should be

reflected in the law. To understand Moral Asymmetry, it helps to focus on an

example of a simple war where country X wrongly invades country Y, with

devastating results for Y’s citizens if X takes control. Y responds by going to

war with X. X’s combatants then kill some of Y’s combatants and vice versa.

Moral Asymmetry implies that whereas Y’s combatants typically permissibly

kill X’s combatants, X’s combatants typically wrongly kill Y’s.

Here is the basic argument for Moral Asymmetry. It is normally wrong

to kill a non-consenting person unless that person is liable to be killed. A

person is liable to be killed only if she lacks a right not to be killed for the sake

15 See, also, Crawford Identifying the Enemy ch.8.

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of some goal that can be secured by killing her. By threatening Y’s citizens,

X’s combatants make themselves liable to be killed to protect Y’s citizens.

Thus Y’s citizens permissibly kill X’s combatants, as long as further conditions

such as necessity and proportionality are satisfied.

Their legitimate acts of self-defence do not make Y’s combatants liable

to be killed to avert the threats they pose to X’s combatants. And Y’s

combatants do not consent to be killed. They thus have a right not to be killed.

Killing them is therefore normally wrong. And even if they didn’t have a

right not to be killed, X’s combatants kill them in order to secure their aim of

invading Y, which is an unjust goal. They could refrain from killing them, and

preserve their own lives, by standing down. So killing them is unnecessary to

achieve a valuable goal. Therefore, X’s combatants wrongly kill Y’s, whereas

Y’s combatants permissibly kill X’s.

This very general argument only supports the conclusion that it is

normally wrong for unjust combatants to kill just combatants. There are

exceptions, the most important of which is that just combatants sometimes act

disproportionately, making them liable to be harmed or even killed. But even

if there are several exceptions of this kind, the general argument for Moral

Asymmetry seems powerful, and seems practically important – it explains the

powerful intuition that Nazi combatants wrongly killed Allied combatants in

WWII, but not vice versa, for example.

Not everyone accepts this argument. Some think it fails because wars

are conducted between states, and combatants are just state tools.16 But a

person does not lose her right not to be killed by being a tool of a state that is

rightly defending its citizens against wrongful aggression. Y’s combatants

16 Although it is not clear, this may have been Jean-Jacques Rousseau’s view.

See The Social Contract (London: Penguin, 1968) 56-7. See, also, Roberts ‘The

Principle of Equal Application of the Laws of War’ in D Rodin and H Shue

Just and Unjust Warriors: The Moral and Legal Status of Soldiers (Oxford: OUP,

2008)

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thus retain their rights not to be killed. Similarly, X’s combatants do not act

permissibly by acting as tools of the state. X’s combatants choose to be tools of

a state that commands them to kill people with a right not to be killed. They

ought not do this. The fact that unjust states are responsible for unjust wars, if

it is a fact, does nothing to diminish the responsibility of individual

combatants for fighting in them.

Some object that just combatants consent to be killed, and thus give up

their rights.17 But this is also false. Here is what consent to harm involves: X

consents to harm by Y if X intentionally and directly releases Y from a duty

that she owes to X not to harm her.18 It is not very plausible that those on the

just side intend to release those on the unjust side from duties they owe them

not to kill them. And even if they did, their consent would not be valid,

because unjust combatants wrongly restrict their opportunities to secure their

just aims without being harmed.19 Although many just combatants are willing

to put themselves in harm’s way for the sake of the cause for which they fight,

this is nothing like valid consent to be harmed, and it does not plausibly

imply that those killed lack rights not to be killed.20

Some might claim that combatants on the unjust side are often justified

in posing threats to those on the just side because of the costs they will suffer

17 Something like this idea is defended in T Hurka ‘Liability and Just Cause’

(2007) 20 Ethics and International Affairs 199. 18 For different defences of this view of consent, see, for example, D Owens

Shaping the Normative Landscape (Oxford: OUP, 2012); T Dougherty ‘Yes means

Yes: Consent and Communication’ (2015) 43 Philosophy & Public Affairs 224; V

Tadros Wrongs and Crimes (Oxford: OUP, forthcoming) ch.11. 19 There is plenty of disagreement about how the validity of consent depends

on coercion, but almost everyone converges on this case. See, for example, A

Wertheimer Consent to Sexual Relations (Cambridge: CUP, 2003); Tadros

Wrongs and Crimes ch.12. 20 See, also, McMahan ‘The Morality of War and the Law of War’ 24-7.

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if they do not do so. For example, some combatants on the unjust side are

threatened with imprisonment, or sometimes worse. Perhaps these threats

sometimes justify participating in an unjust war. But they are normally

insufficient. It is normally wrong to kill a person to save one’s own life. The

justification offered would seem valid, then, only if failing to comply with the

threat would result in much more harm than the person causes by complying

with it, which will rarely be so.21

It is more plausible that many unjust combatants are excused for

killing just combatants because of the epistemic difficulties that war poses, the

threats and social pressures that combatants face, and the terror and chaos

that pervade in war. I think that just war theorists often exaggerate this idea,

but even if it is right it is no challenge to Moral Asymmetry because Moral

Asymmetry is a view about wrongdoing, not a view about responsibility or

blameworthiness for wrongdoing. As a person normally needs an excuse only

if she acts wrongly, the view that unjust combatants are typically excused

presupposes rather than challenges something like Moral Asymmetry.

III. Why Converge?

I will consider a simple law that makes it an offence against international

humanitarian law to kill combatants who are engaged in legitimate acts of

war to defend others against unjust attacks.22 Such a prohibition would be

21 See, further, V Tadros ‘Duress and Duty’ in S Bazargan and S Rickless The

Ethics of War: Essays (Oxford: OUP, forthcoming). 22 An alternative approach is to extend the prohibition on resort to force to

individual combatants, rather than creating a prohibition in international

humanitarian law. This would result in a division of labour to ensure that

wrongful killing in war is prohibited. See A Haque ‘Laws for War’ in J D

Ohlin Theoretical Boundaries of Armed Conflict and Human Rights (Cambridge:

CUP, 2016). As it stands, the prohibition on resort to force applies to states, at

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subject to qualifications and defences that need not distract us here. I will call

such a law a prohibition on killing just combatants for short.

I first reject Henry Shue’s general argument for convergence between

law and morality. This will enable us better to understand reasons why law

and morality might come apart so that we can assess these reasons in the

particular cases we are concerned with. Roughly, Shue claims that the

morality of war just is the rules that rightly govern the conduct of individuals

fighting in wars. Thus, he argues, there is no real room for divergence

between law and morality, at least if the law is as it should be, because the

considerations that shape the rules that govern the conduct of individuals

fighting in war are the moral considerations that apply to combatants.23

Here is one simple response: the law does not plausibly reflect or

determine all of the rights and duties that people have during war, any more

than they do in any other part of life. 24 One reason why is that some

consequences of creating a law provide reasons for and against creating it, but

have no bearing on the moral obligations of those governed by it.

least as far as the United Nations Charter is concerned. Article 2(4) applies to

members of the UN, and the members are states, not individuals. Article 51

does mention individual rights of self-defence, but that only indicates a

sufficient condition of the legal use of force, not a necessary condition. I lack

the space to adequately to adjudicate between the extension of these different

legal regimes, but I suspect that it is better to extend IHL, for that is the body

of law that applies to wrongful acts committed during war, rather than the

wrongful decision to go to war, and that is what we are concerned with. 23 See H Shue ‘Do We Need a ‘Morality of War?’ in Rodin and Shue Just and

Unjust Warriors: The Moral and Legal Status of Soldiers. 24 See, also, J McMahan ‘The Morality of War and the Law of War’ and

Roberts ‘The Principle of Equal Application of the Laws of War’ both in Rodin

and Shue Just and Unjust Warriors: The Moral and Legal Status of Soldiers.

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For example, some consequences of creating a law arise because of

how people will respond to it. But how people will respond depends on

dispositions and tendencies that do not affect their duties. The fact that a

proposed legal norm will be misapplied by people with bad dispositions, or

exploited by those with bad motives, is a reason against creating it. But

people do not lack moral duties because they will misapply these duties, or

exploit them if they have bad motives.

Consider the legal rule that the defence of self-defence is available to

defendants only if they were responding to an imminent attack. The law is

more restrictive than morality, for it is morally permissible to use necessary

and proportionate force to non-imminent threats. There are reasons against

broadening the law to converge with morality: some people will mistakenly

believe that it is necessary to use force against non-imminent threats, leading

to an increase in the rate of wrongful violence; and gang members will exploit

any broader law to justify attacks on rival gangs.25 I do not claim that the law

is right; there are also reasons to favour convergence. I claim only that the

relevant reasons have nothing to do with our moral obligations, and may be

decisive. As a consequence, the morally best law may not reflect morality.

IV. Three Functions of the LOAC

My argument for convergence rests on the idea that the LOAC ought to have

three functions. A prohibition on killing just combatants can help it to fulfil

these functions, and their facilitating their performance is proportionate to the

evils that the law might cause. This section is concerned with the functions of

the LOAC: not the functions that they currently have, but the functions that

they ought to have were they best conceived.

25 Related arguments apply to the jus ad bellum imminence requirement for

going to war.

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Many take the central legitimate function of the LOAC to be to reduce

the destructiveness of war, or to limit its savagery, or more simply to prevent

harm.26 This is roughly right, but we get a better understanding of the proper

content of the LOAC by understanding how this function is performed in

central cases. And although harm reduction is the most important function of

the LOAC, it is not their only function. Even though the domestic context and

the context of war are quite different, it is instructive to compare the LOAC to

criminal laws.

The LOAC, like criminal laws, have a guidance function. They aim to

change behaviour by securing conformity and compliance with the law. In the

case of mala in se crimes, the main reason to secure conformity and

compliance is to prevent the wrongs that the law prohibits. For example, the

criminal law encourages people to conform or comply with the law

prohibiting murder in order to prevent the evils of murder. And the evils of

murder make it wrong. Conformity with the law, in this case, ensures

conformity with the moral norm that underpins it. In less central cases, the

law prevents harm indirectly. That is why laws that prevent harm need not

prohibit conduct that is itself harmful.27 But this should not distract us from

the simple idea that the normal way that the law prevents harm is by

prohibiting conduct that is both wrongful and harmful.

Second, the LOAC, like criminal laws, have an accountability function.

They play a role in trials. Trials determine whether the defendant has acted

wrongly, whether she was responsible for doing so, and whether she was

26 See, for example, C Kutz ‘A Modest Case for Symmetry’ in On War and

Democracy (Princeton: Princeton University Press, 2016) 70; Waldron ‘Deep

Morality and the Laws of War’. 27 See, for example, J Gardner and S Shute ‘The Wrongness of Rape’ in J

Gardner Offences and Defences: Selected Essays in the Philosophy of Criminal Law

(Oxford: OUP, 2007); J Edwards ‘Harm Principles’ (2014) 20 Legal Theory 253;

Tadros Wrongs and Crimes ch.6.

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excused. Where the defendant is convicted, the court publicly blames

wrongdoers and warrants punishment. The laws that guide citizens play a

role in accountability practices: they set out the wrongs that defendants are

held to account for committing. The law of murder, for example both aims to

guide people, and to guide courts in holding people accountable for murder.

But other laws supplement them. Most importantly for our purposes, laws

setting out excuses do not guide the conduct of citizens; rather they determine

whether those who violate the law ought to be held accountable and

punished.

Third, the LOAC, like criminal laws, have a symbolic function. By

criminalizing serious wrongdoing, officials take a public stance on that

wrongdoing, indicating that it is the kind of thing that warrants enforcement,

condemnation and punishment. This symbolic function can partly be

performed without prosecuting people for breach. For example, by

criminalizing rape, the state indicates that the duty not to rape is enforceable

by the state, and that the state is warranted in holding people to account for

rape by publicly condemning and punishing them in a criminal court.

V. Guiding Just Combat

Can a prohibition on killing just combatants contribute to the performance of

these functions? Focus on the guidance function first. The prohibition aims to

guide people not to kill just combatants, which is obviously a worthy goal.

But some doubt that such a law could offer effective guidance, or that it could

do so justly.

Waldron, for example, argues that the laws of war must not impose

unreasonable burdens on combatants or they will be impossible to

administer. They must be tailored to circumstances of panic, anger and great

danger. Obviously, our expectations of a person to comply with the law are

reduced if her life will be threatened by compliance, especially where the

danger is imminent, and rational reflection cannot be expected. This might

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give them an excuse, and make punishing them unjust. But it is no reason

against setting out clearly the moral obligations that apply in war in law. If

anything people who are in circumstances that make it difficult to determine

what they are required to do are entitled to guidance if it can be provided.

After all, people themselves have an interest in not killing wrongfully.

Furthermore, fear and anger are not always to be expected in war. The laws of

war apply to people who launch attacks from positions of relative safety –

drone pilots being only one of the more extreme examples. They also guide

those who command others to act, and people deciding whether to go to war

in the first place.28

McMahan offers a different reason a prohibition on killing just

combatants is an ineffective guide: almost all unjust combatants believe that

their cause is just, or will assert that it is if they do not believe it, and such a

prohibition would therefore fail to alter behaviour.29 This conclusion seems

unduly pessimistic. Even if McMahan was right that people fighting in unjust

wars would not be influenced by a prohibition on killing just combatants, it

might influence the decision of potential combatants to go to war.

Suppose that killing just combatants was legally prohibited, the

existence of the prohibition was well known, and NGOs devoted resources to

educating people about the prohibition. Some people may be less inclined to

join militaries that they think will be commanded to fight unjust wars, to

leave militaries of that kind, to refuse to fight, to fight less effectively if they

do go to war, and to desert.

It is hard to know what the long-term effects of the law might be, but

perhaps only a small proportion of people would be influenced in this way.

Even if so, though, revising the law might be justified. This change might

have two effects. First, it might make governments inclined to engage in

28 See, also, A Haque ‘Law and Morality at War’ (2014) 8 Criminal Law and

Philosophy 79, 91. 29 ‘The Morality of War and the Law of War’, 27-8.

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unjust wars less likely to plan to do so. This might be so because they will be

less confident that they can gain enough popular and military support to

make war feasible and politically attractive. Even if the law affects only a

small proportion of people, it might be effective at the tipping point,

preventing some unjust wars.30 Assuming that it does not have profound

negative effects, it would be worth prohibiting the killing of just combatants if

this would prevent a single unjust war, given how bad war is.

Second, it might reduce the harmful effects of unjust wars by reducing

the number of unjust combatants, by strengthening the resolve of

conscientious objectors, and by strengthening the resolve of those inclined to

desert. In all of these cases, the law will typically be effective only for those

people who see other reasons to comply with it; that is also true of domestic

criminal law. But there must be many such people.

Some might think that the LOAC could only be even modestly

effective if it was reinforced by practices of responsibility. If no one is held

responsible for violating a law, no one will be motivated to comply with it.

Many think that it is wrong to hold combatants accountable for killing just

combatants, because they are typically excused for participating. The

prohibition on killing just combatants, therefore, cannot be made effective

without unjustly punishing those who violate it. Later, we will see that it need

not be wrong to hold unjust combatants responsible for killing just

combatants. But let us assume, for the moment, that this is not so.

Accountability practices may make the law more effective. But there

are other ways to secure compliance. People comply with laws both to avoid

sanctions, but also because they see the law as valid. They can be encouraged

to comply by a systematic programme of education, and the development of

an informal culture, which disseminates the rationale for the law. The

30 For good analysis of tipping point arguments like this within a

consequentialist framework, see S Kagan ‘Do I Make a Difference?’ (2011) 39

Philosophy and Public Affairs 107.

18

existence of the law can contribute to the development of these education

programmes and informal cultures – it provides a clear international standard

around which efforts to develop such programmes and cultures can gather.

Indeed, whilst there is some room for dispute, a common view is that

not all violations of international humanitarian law violate international

criminal law. Prosecutions are competent only if the violation of international

humanitarian law is serious.31 And prosecutions only actually occur in very

serious cases. It does not seem true that this makes international

humanitarian law completely ineffective in preventing non-serious breaches.

VI. Accountability for Wrongful Killing in War

We have seen that many argue against Legal Asymmetry because combatants

are excused, but that this confuses the guidance and accountability functions

of the law. But I have also suggested that the guidance function of the law

would be more effective if its accountability function could be performed. Are

critics right that this function cannot justly be performed because combatants

are excused? I doubt it.

First, we have seen that standard excuses that are offered on behalf of

unjust combatants, which derive from the mortal danger they face, do not

apply to all combatants. Furthermore, a person is not normally excused if

they are responsible for creating the relevant excusing conditions, and lack a

justification for doing so. This applies to many combatants who fight in

patently unjust wars.

Finally, it is not very plausible that fear and anger fully excuse

wrongful killing. When a person has a full legal excuse, in the sense that I

mean by it, the grounds of their excuses undermine any demands that can

legitimately be made of the person by holding her responsible for

31 See, for example, Article 8 of the Rome Statute of the International Criminal

Court.

19

wrongdoing by legal institutions. I emphasise this particular understanding

of full excuses for the following reason. The justification of accountability and

punishment that I favour draws on the idea that it is permissible to treat

wrongdoers in certain ways because of the duties that they incur by acting

wrongly. I call this the ‘duty view’ of punishment.32

Very roughly, when a person is held responsible for wrongdoing in

criminal or international court, and that person is punished, demands are

made of that person to respond to her wrongdoing, both by acknowledging

that the wrongdoing was attributable to her, and also by enforcing other

obligations that she has incurred in the light of it (or doing the equivalent to

enforcing these obligations). The most important obligations are protective –

she is forced to be involved in a deterrence regime by being punished, and

that protects others from future wrongdoing, both by her and by others.

If this is the right justification of punishment, a person has a full excuse

only if her excuses her undermine the duties that underpin legal institutions.

This is plausible, for example, in cases where the person completely lacks

responsibility for her wrongdoing, such as child soldiers who are violently

indoctrinated from a young age. It is much less plausible where the wrongful

killing arises due to fear and anger. These conditions make one’s obligations

to respond to one’s wrongdoing less stringent, affecting proportionality, but

they do not negate them altogether. If those without a full excuse are

punished only in proportion to the stringency of their duties, they are not

treated unfairly.

A further objection is that even if it would not be unfair to hold unjust

combatants responsible for their wrongdoing, doing so is impractical, because

it is impossible to determine who has acted wrongly in war. One reason that

32 See, especially, The Ends of Harm: The Moral Foundations of Criminal Law

(Oxford: OUP, 2011).

20

has been given is that it is difficult to determine which wars are unjust.33A

second is that it is difficult to discover what any individual has done during a

war, and whether their particular acts are wrong, given that wars are

complex, and some have just and unjust phases.34

I agree that these difficulties exist, but the objection nevertheless fails.

First compare the world of criminal justice: the fact that it is difficult to tell

whether people have acted wrongly is not a powerful reason against

criminalizing grave wrongs. For example, the conviction rate of rape in the

UK has been estimated at around 7%. A central reason is that it is difficult to

convince juries that complainants do not consent to sex to the requisite

standard of proof. Various recommendations have been implemented to

overcome this difficulty, but the low conviction rate has remained fairly

constant. The fact that juries find it hard to distinguish wrongful from

permissible sex, though, hardly warrants decriminalizing rape. One obvious

and decisive reason is that there are sufficient clear cases where the

complainant was not consenting, and in those cases defendants are regularly

convicted.

Similarly, it is often difficult to establish to a high evidential standard

that a war was unjust, or that a person wrongly killed in war. Perhaps

impartial international institutions could be developed which would do a

good job in making assessments of a wide range of wars.35 This does not seem

unrealistic, but some might think that such institutions might not be very

effective, or very desirable even if they were. But there are plenty of clear

33 See, for example, Roberts ‘The Principle of Equal Application of the Laws of

War’ 248-9. 34 See McMahan ‘The Morality of War and the Law of War’ 32. 35 On which, see J McMahan ‘The Laws of War’ in S Besson and J Tasioulas

The Philosophy of International Law (Oxford: OUP, 2010); ‘War Crimes and

Immoral Action in War’ in R A Duff, L Farmer, S E Marshall, M Renzo, and V

Tadros The Constitution of the Criminal Law (Oxford: OUP, 2013).

21

cases, where wars are patently unjust, and there is no plausible reason to kill.

The acts of German combatants in WWII and those fighting for Fascism in the

Spanish Civil War are clear examples.

Furthermore, courts already rely on judgements about the justice of

wars: UK courts, for example, regularly convict and punish people under

terrorism law for preparing to participate in wars in the Middle East. In doing

so, they make the implicit judgement that these wars are unjust.36 In cases

where there is little confidence that combatants have acted wrongly,

prosecutions ought not to occur, and if they do defendants ought to be

acquitted. This can be ensured reasonably well by adopting the standard

evidential and procedural protections found in the criminal law.37

Finally, even were the relevant excuses and epistemic difficulties to

rule out anything like criminal trials and punishment, other accountability

practices may be justified, such as restorative justice practices and truth and

reconciliation commissions. Such practices typically aim to respond to serious

wrongdoing without inflicting heavy burdens of criminal punishment on

wrongdoers. Because they are less punitive, some of the restrictions involved

in criminal trials may be relaxed. A prohibition on killing just combatants

could have an important role to play in such practices.

It is important to discover why people wrongly kill in war. Unjust

combatants, even those who are completely excused, can be expected to

provide an account of what they did and why. This truth-finding mission is

important not only to victims of wrongdoing and their families; it is

important for wrongdoers, who have a powerful interest in knowing whether

they have acted wrongly, even if they are excused. And it is important so that

people can reconcile with each other, and can learn the lessons of history. A

prohibition on killing just combatants can contribute to this truth finding

36 For discussion, see J Hodgson and V Tadros ‘The Impossibility of Defining

Terrorism’ (2013) 16 New Criminal Law Review 494. 37 See, also, Haque ‘Law and Morality at War’, 93.

22

mission by identifying the conditions under which killing is wrongful, even if

it is excused.

Perhaps it might be argued that the relevant truth-finding processes

are effective only because the prospect of punishment sits in the background.

This may often be true, but it is no objection. As people are morally required

to participate in such practices, it may be permissible to punish them for

failing to participate, even if it is not permissible to punish them for the acts of

war that make their participation required.

Finally, even if the accountability and guidance functions of a

prohibition on killing just combatants cannot be secured fairly, its symbolic

function might be sufficiently important alone to justify creating it. The view

that it is morally permissible to kill combatants on either side of a war is

probably still quite widespread, even if it is beginning to erode. This view is

deeply disrespectful to combatants on the just side. The fact that their deaths

are wrongfully caused ought to be generally acknowledged. A law

prohibiting this conduct can play an important role in encouraging people to

acknowledge this, even if it does nothing to diminish the harms caused in

war.

VII. Bad Effects of the Law

A law prohibiting the killing of just combatants can fulfil all three functions of

the LOAC. But perhaps the costs of creating it are too high. I cannot consider

all of the relevant arguments, but I focus on three that seem the most

important.

i) Biased and Unjust Enforcement

One objection is that a prohibition on killing just combatants will be unfairly

enforced because participants in a conflict will inevitably enforce the law

23

against their enemies.38 If this were done, punishment might often be inflicted

on just combatants, or disproportionately, or in a cruel way.

But this is not inevitable. Although states are currently legally

permitted to prosecute those they are in conflict with, this institutional

position is not inevitable. A prohibition on killing just combatants might be

accompanied by a prohibition on partisan enforcement. Suppose that a law

prohibiting the killing of just combatants was created, and international

institutions such as the ICC were further developed to hold people

accountable for violating the law. The law explicitly prohibits participant

states from punishing those who violate the law. This would lead to an

increase in partisan punishment only if there are states with two features:

first, they will punish just combatants only if there is a law prohibiting the

killing of just combatants, but second, they will do so in defiance of a law that

prohibits enforcement by states participating in the war. Given that states are

unlikely to have both features, I doubt that the concern with partisan

punishment provides a significant consideration against a prohibition on

killing just combatants.

It might be argued that international institutions are too immature to

carry out this function well. McMahan, for example, argues that there are

stronger reasons to expect convergence between criminal law and morality

than the laws of war and morality because criminal justice institutions are

better developed, and so have more capacity to respond adequately to

wrongdoing.39 Perhaps there is this difference in capacity. But the short-term

costs involved in international institutions performing poorly may be worth

bearing to secure the long-term goal of reducing the number of unjust wars,

and the number of people who fight in them.

38 See, for example, Kutz ‘A Modest Case for Symmetry’ 69; J McMahan ‘The

Morality of War and the Law of War’ 29-30; A Roberts ‘The Principles of the

Equal Application of the Laws of War’ 242. 39 The Morality of War and the Law of War’ 34.

24

Institutional development cannot occur without the development of

the substantive law. Compare the history of the criminal law and criminal

justice institutions. Core crimes, such as murder and rape, predated the

development of sophisticated institutions of criminal justice by thousands of

years – it wasn’t until the nineteenth century that trials were anything more

than swift and informal affairs. Increasing institutional sophistication in the

nineteenth century went with the development of crimes outside the core

such as regulatory offences.40 It also went with the development of a more

sophisticated set of mens rea requirements, and defences, that were created in

response to an increasing concern to ensure that the innocent were not

punished for core wrongs. This was essential to ensure the legitimacy of the

criminal justice system.41 These developments in turn led to new evidential

standards – the modern standard and burden of proof in criminal trials, for

example, were not firmly established in the nineteenth century.

In a similar way, the development of international institutions and the

development of the LOAC must go together. The development of more

sophisticated institutions to distinguish wrongful and permissible conduct in

war depends on a set of substantive norms that recognizably relate to the

morality of war. Without a basic set of prohibitions on serious wrongdoing,

there is little for institutional practice to focus on, and poor institutional

development is to be expected. The creation of a law prohibiting the killing of

just combatants will create the pressure to develop institutions that can more

accurately distinguish wrongful from non-wrongful conduct in war. In the

course of developing our institutions, new defences will be created as

combatants who are held to account argue that their conduct was permissible.

None of this can occur without a change in the LOAC. If substantive law

40 See, for example, N Lacey In Search of Criminal Responsibility: Ideas, Interests,

and Institutions (Oxford: OUP, 2016) ch.4. 41 See, for example, L Farmer Criminal Law, Tradition and Legal Order

(Cambridge: CUP, 1996) ch.1; Lacey In Search of Criminal Responsibility 139-40.

25

waits on more sophisticated institutions that can distinguish wrongful from

non-wrongful conduct, it will wait forever.

ii) Reducing the Incentives not to Commit More Egregious Wrongs

A second argument is that a law prohibiting the killing of just combatants will

incline people to total war, or to continue fighting where they would

otherwise surrender. If unjust combatants think that they will be punished for

killing just combatants, they lack an incentive not to perform even worse acts,

such as killing non-combatants, or to continue performing wrongful acts

where they might otherwise stop.42 Thus, a law prohibiting the killing of

unjust combatants will increase the number of gravely wrongful acts

performed, and will make war more destructive, which conflicts with the

central aim of the LOAC.

Even if this incentive problem exists it is a massive overreaction to

claim that this supports deregulation. There is a familiar solution in the

criminal law that is instructive in the case of war. Take a person who burgles

a house, and who is seen by the homeowner. If burglary is prohibited, this

person’s incentive not to kill the homeowner is reduced; she has an incentive

to do so to avoid punishment; she lacks a disincentive not to given that if she

is caught she will be punished regardless of whether she has killed.

42 See, for example, McMahan ‘The Morality of War and the Law of War’ 30.

The view that something like the current law can be justified on the grounds

that it directs unjust combatants to commit less egregious wrongs is defended

in S Lazar Sparing Civilians (Oxford: OUP, 2015). See, also, Haque ‘Laws of

War’. For my own part, I doubt that killing just non-combatants is morally

worse than killing just combatants, but I set this aside. For discussion, see V

Tadros ‘Moral Distinction: Vulnerable and Defenceless’, Law and Philosophy,

forthcoming.

26

Needless to say, not many people respond to this problem by

advocating decriminalizing burglary! The obvious solution, which we have

understood at least since Jeremy Bentham’s work,43 is to impose differential

sentences on burglars and murderers, especially murders that are committed

in the course of a burglary. Similarly, international laws and institutions can

adjust responses to different wrongs to create the desired incentive structure.

And there can be latitude to decide whether to prosecute, and what for,

depending on early surrender.

iii) Reducing Effectiveness on the Just Side

Perhaps the most powerful reason against Legal Asymmetry is that it will

reduce the ability of comparatively just, as well as comparatively unjust,

countries to fight. Furthermore, it might be argued that the effect on the

former is greater, and that this will have bad consequences.

The effects on the military capacities of comparatively just countries

might be thought greater because their citizens are more strongly inclined to

follow international law than those of comparatively unjust countries. This is

because comparatively just countries foster a culture where international

norms are respected, and because their citizens are typically better educated,

and so understand what these norms require. Citizens of comparatively just

countries are thus more likely to refrain from joining the military, or refusing

to fight in wars, if they think that their government will engage in unjust

wars. Furthermore, governments of comparatively just countries will think

even more carefully about engaging in wars that might be unjust if they think

that their combatants will be held to account through international

institutions if they turn out to have acted wrongly.

43 See The Principles of Morals and Legislation (New York: Prometheus Books,

1988) ch.XIV.

27

This might reduce the number of just wars, which might be regrettable.

It might also reduce the deterrent effect that comparatively just countries

provide to comparatively unjust countries: the latter might consider

themselves free to engage in unjust acts safe in the knowledge that

comparatively just countries are hampered from responding. And it might

reduce the effectiveness of comparatively just countries in the wars they fight.

The importance of these considerations is hard to assess. But I doubt

that they count decisively against Moral Asymmetry. At most, the problem

calls for caution in prosecuting cases where it is questionable whether the war

is just. First note a similar concern in domestic policing: that robust practices

where the police are held accountable for wrongdoing in policing operations

will reduce the effectiveness of policing, and will thus reduce its deterrent

effect. Not many people respond to this problem by advocating the

deregulation of police violence. On the contrary, in the UK at least, police

accountability is becoming more robust. It is at best doubtful that

accountability reduces effectiveness. In fact, it has some countervailing effects.

As accountability practices develop, the culture of policing is increasingly

professionalized. The police gain the confidence of working within a carefully

controlled legal framework. Within this framework, they can have greater

confidence that their conduct is not wrongful, and this may make them more

effective. Furthermore, the effectiveness of policing depends on popular

support, and this typically increases when people think that the police will be

held accountable for wrongdoing.

Over the longer term, the same thing might be true in the case of war.

As military operations are subject to greater legal scrutiny, those who fight for

comparatively just countries are more likely to have the confidence that the

wars they participate in are just. This confidence is likely to make them more

effective, as they are more likely to be committed to the causes they fight for.

And their confidence will be further boosted by the increased support they

can expect from their domestic populations, and from the international

community of comparatively just countries.

28

Of course, the overall effects of the competing pressures I have

identified are difficult to assess. But the view that we should not make killing

of just combatants unlawful because we are afraid that it will make

comparatively just countries weaker seems unduly pessimistic about the

ability of the law to strengthen the resolve of those on the just side whilst

weakening that on the unjust side.

Of course, I have only responded to three concerns about Legal

Symmetry. I hope at least to have shown that legal institutions can respond to

a range of problems without taking the extreme option of deregulating

wrongful killing.

VIII. Moral and Legal Non-Immunity

Even more controversial than the view that killing just combatants ought to

be legally prohibited is the view that killing unjust non-combatants ought to

be legally permitted. I will argue in favour of this view, but there are

significant empirical difficulties that make this case less compelling than the

case for prohibiting the killing of just combatants. I begin with a brief defence

of Moral Non-Immunity before addressing the legal questions.

i) Moral Non-Immunity

Here is a standard argument for Moral Non-Immunity. It is often permissible to

kill a person to avert a threat if that person is liable to be killed to avert it. A

person becomes liable to be killed to avert a lethal threat that is unjustly

posed if that person is responsible for causing or contributing to it. This is so

even if the person’s contribution is too remote from the lethal threats posed in

war for that person to directly participate in hostilities. Many unjust non-

combatants are responsible for causing or contributing to unjust lethal threats

that are posed in war. Therefore, many unjust non-combatants are liable to be

killed to avert lethal threats posed in war.

29

One challenge to this argument aims to show that mere responsibility

for causing or contributing to a lethal unjust threat is insufficient for liability

to be killed to avert it. Culpability, even a high degree of culpability, is

required. In response, it is not plausible that it is only permissible

intentionally to kill a person who directly poses a threat if that person is

highly culpable for posing it. And even if it was, many unjust non-combatants

intend to contribute to unjust threats, and intentionally posing an unjust

lethal threat is normally sufficient to make a person liable to be killed to avert

the threat.

Perhaps it will be objected that many non-combatants intentionally

contribute to unjust threats are excused for doing so, and so their culpability

is insufficiently high to make them liable to be killed. But even if this is true in

some cases, it is untrue in many others – those who manufacture weapons to

support patently unjust wars, for example, are often highly culpable for doing

so.

A second challenge claims that the contribution that unjust non-

combatants make to the war effort is ‘too small’ to make them liable to be

killed. Some think that relatively few non-combatants are liable to be killed on

this basis.44 Those who defend this view have done relatively little to clarify

what it means for a contribution to be small, let alone to show that liability to

be killed depends on the size of the contribution that a person makes. Though

I cannot show this here, the metaphysical questions are very difficult, and the

prospects of establishing that liability depends on the magnitude of a person’s

causal contribution are dim.45

To reinforce this idea, it is quite plausible that a person can become

liable to be harmed to avert a threat without making any causal contribution

44 See, for example, ‘Guns, Food, and Liability to Attack in War’ (2009) 120

Ethics 61. See, also, Cosmopolitan War (Oxford: OUP, 2012) 76-7; Killing in War

(Oxford: OUP, 2009) 225. 45 See V Tadros ‘Causal Contributions and Liability’, unpublished ms.

30

to the threat. There are many potential routes to liability without causation,

including attempts, vicarious liability, and participating in a shared plan.46

Even if these routes to liability are insufficient for the person to be liable to be

killed, they are sufficient to contribute to an overall argument for the

permissibility of killing non-combatants.

Finally, as defenders of the scalar view acknowledge some non-

combatants clearly make large contributions to unjust threats, on any account

of the way in which causation is scalar. For example, those involved in

planning operations and those involved in developing technology used on the

front line often make large contributions to threats posed in war; larger than

the contributions of many combatants.

A final objection is that the argument offered for non-combatant

liability implausibly permits terrorism. A very powerful argument is needed

to overcome the brute intuition that bombing civilians to terrorize

governments into surrender is permissible. But, in response, terrorism has

distinctive features that make it harder to justify than killing a person to

eliminate a threat that they will otherwise contribute to. In standard cases of

terrorism, the horrific deaths of some people are used to influence the

behaviour of others. This is especially hard to justify. For this reason, the

argument for Moral Non-Immunity does not support, for example,

indiscriminate starvation blockades perpetrated by the British against the

Germans in WWI, which aimed to encourage starving civilians to overthrow

46 For further discussion of some of these cases, see, for example, S Bazargan

‘Complicitous Liability in War’ (2013) 165 Philosophical Studies 177; V Tadros

‘Orwell’s Battle with Brittain: Vicarious Liability for Unjust Aggression’ (2014)

42 Philosophy and Public Affairs 42; V Tadros ‘Causation, Culpability, and

Liability’ in C Coons and M Weber The Ethics of Self-Defense (Oxford: OUP,

2016).

31

their government, or the bombing of Hiroshima and Nagasaki at the end of

WWII.

IX. A Rough Proposal

A standard argument in favour of Strict Legal Immunity is that relaxing non-

combatant immunity will lead to total war. We are now well placed to

respond to this concern. Here is what I think people mean by a total war.

Consider a war between two states, X and Y. A total war is a war where

everyone in state X is treated as a legitimate target of attack by those in state

Y, and everyone in state Y is treated as a legitimate of attack by those in state

X.

It is reasonable to suppose that in many wars, both sides will believe

that their cause is just, and the cause of the opposing is unjust. If the law

permits the killing of non-combatants, decision makers in state X will believe

that they are legally entitled to kill both combatants and non-combatants in

state Y, and vice versa. Therefore, combatants in state X will treat everyone in

state Y as a legitimate target of attack, and vice versa.

Of course, total war is not troubling because so many people are

treated as a target, but rather because of who will be killed, and in what

numbers. As we will see, increasing the legitimate targets in war does not

necessarily increase the death toll, and may have the opposite effect.

However, it is plausible enough that a combatant is more likely to attack

another person if he believes that he is legally entitled to do so. It is at least

sometimes true that total war will be more destructive than a more

constrained war.

But if Legal Non-Immunity were to reflect Moral Non-Immunity, nothing

like total war would follow, at least if people are at all inclined to abide by the

law. The law would only permit targeting non-combatants to prevent them

from contributing to the war, and only if doing so would be a necessary and

proportionate way of preventing unjust aggression.

32

This could not plausibly support, for example, carpet-bombing civilian

populations in cities. It is not plausible that enough civilians contribute to the

war effort to justify this; the method of securing victory would be prohibited;

and doing it is normally insufficiently effective to justify the casualties. The

existing legal prohibition on securing victory by terrorizing civilians would

thus be maintained.47 We are concerned with a much narrower exception to

the rule prohibiting intentional attacks on non-combatants.

This extension of the law might be achieved by expanding the class of

combatants to include not only those who directly participate in hostilities,

but also those who do so indirectly. But perhaps the better way is to establish

a defence to an offence of attacking non-combatants. This alternative seems

better in part because it indicates clearly the idea that attacks on those who

participate indirectly are rarely permitted. This would involve retaining the

distinction between civilians who directly participate in hostilities and those

that do not, roughly as the law is currently set out. Those who attack people

who directly participate on the unjust side would not need to use the new

defence.

Here is a rough proposal to help focus the discussion:

Qualified Legal Immunity:

1) It is an offence to intentionally attack non-combatants during war.

2) A person is entitled to a defence if

a) Attacking the person could reasonably be expected to prevent

significant harm that would otherwise result from her

contribution to the military operations of a nation, state or

group engaged in an unjust war; and

47 Additional Protocol to the Geneva Convention II, Art.13(2).

33

b) Attacking the person was done only in order to prevent her

from making that contribution, and not in order to carry out

reprisals, or to cause terror or alarm; and

c) A reasonable person would conclude that attacking this person

was the least harmful means to avert the threats that would

otherwise be posed as a result of the contribution that she

would make.

Obviously, I do not intend this to be a final draft of a proposed law, but only a

working proposal that might be improved on. Assessing whether something

like this ought to be adopted requires a much more careful assessment of the

potential benefits and risks. We can make that assessment by comparing Strict

Legal Immunity with Qualified Legal Immunity, and variations on that proposal.

X. Why Converge (Again)?

A very simple reason in favour of greater convergence is that a law that

prohibits all killing of non-combatants fails to respond to the reasons why it is

morally permissible to kill non-combatants in the limited circumstances

outlined in Section IV.

i) Why Strict Non-Combatant Immunity is Harmful

Earlier, I noted that many think that Strict Legal Immunity is justified because

it reduces the destructiveness of war. However, there are some reasons to

think that this is the opposite of the truth: in decisions whom to kill, the law

requires just combatants to draw a sharp distinction unjust civilians in virtue

of the causal proximity of their actions and unjust lethal threats. They must

do this irrespective of facts that are obviously morally salient, such as the

effect that killing the person will have on the prospects of the unjust side, the

expected number of liable people who must be killed to avert the threats that

34

the person contributes to, the expected number of non-liable people who will

be killed in averting the threats they will contribute to, and the expected

number of non-liable people whose lives might be saved by killing the

person.

Take two sets of civilians: the first group directly participates in

hostilities whereas the second does not. Whether a civilian directly

participates depends on the causal proximity between her act and threats of

lethal harm, or the military prospects of the unjust side. Hold the magnitude

of the threat that these people contribute to constant. The threat can be

averted either by killing many directly participating unjust civilians or far

fewer indirectly participating unjust civilians. The law requires just

combatants to kill many more people in this case. The same thing is true

when we hold military advantage constant.

Hold the contribution constant, but suppose that targeting the group

that directly participates in hostilities will result in more non-liable people

being killed as a side-effect than targeting the group that indirectly

participates in hostilities. But suppose that the number killed in either case is

proportionate to the importance of the goal of the just combatant. Again, the

law requires just combatants to kill more people as a side-effect.

Furthermore, hold the number of morally liable people killed constant,

but adjust the magnitude of the harm to non-liable people that will be

prevented, or the probability that such harm will be prevented, or the

contribution to the prospects of the unjust side that will be prevented. The

law requires just combatants to kill directly participating unjust civilians

where doing so will save fewer lives, or has a lower probability of saving

lives, or will do less to secure victory for the just side where they could kill

the same number of indirectly participating unjust civilians where doing so

will save more lives, or will do more to secure victory for the just side.

Consider the most obvious case: giving legal immunity to non-

combatants involved in developing new technology that enhances the

35

military capability of the unjust side.48 Those who do this are normally highly

skilled, and are thus relatively difficult to replace. This in contrast with those

who use the technology, who are often less skilled and are thus relatively easy

to replace. For this reason, much more killing typically has to occur to prevent

new technology from being used once it is developed than to prevent new

technology from being developed in the first place.

For this reason, a state that is permitted to attack those who use the

technology (i.e. combatants) typically must kill many more people to secure

victory than a state that is permitted to attack those who develop technology.

Because this will be harder to achieve, victory will be more difficult to secure.

And even if victory is secured, it will be secured at a greater cost to the

opposing side.

A similar thing is true in cases where a person secures technology to

increase the military resources of the unjust side. Consider a person who is in

the course of securing a large cache of machine guns to support the unjust

side. If this person is not killed, let us suppose, these guns will, in all

likelihood, get to unjust armed forces, significantly increasing the threats

posed. Preventing their use will thus involve killing many combatants rather

than the single person who secures the cache. Furthermore, suppose that

targeting the person who is about to secure the cache will kill few people as a

side-effect. If the guns get into the hands of unjust combatants, in contrast,

averting the threats they pose may result in many civilian casualties.

Finally, consider a person who has stolen oil tankers that will later be

used to cause a large explosion in a military base. Killing the person who has

stolen these might prevent a large number of casualties, especially if it is

difficult to keep track of the tankers. Furthermore, if the tankers are destroyed

closer to the front line, the destruction may cause a greater number of deaths

48 This case prompted some dissent to the interpretation of direct participation

in hostilities by the ICRC. See Melzer Interpretative Guidance on the Notion of

Direct Participation in Hostilities, 57, n.122.

36

of both the liable and the non-liable.49 The law requires just combatants to

divert military resources to those who are more directly engaged in hostilities,

even though this will do less to secure victory, will in all likelihood save

fewer lives of non-liable people, and will involve killing both the liable and

the non-liable in greater numbers.50

Needless to say, problems of this kind create pressure in practice to

interpret whether a person makes a direct contribution by responding to

considerations that are independent of the causal idea that the LOAC focuses

on. For example, those with military expertise typically regard it as

permissible to kill people who build improvised explosive devices or suicide

vests. They justify these acts on the basis of a fishy interpretation of causation,

but they really respond to the fact that waiting until these devices get into the

hands on combatants will result in many deaths, even if the threats can later

be averted.51

Perhaps it might be argued that it is unnecessary to extend the law in

this respect, because it is already permissible to target military objects. But, in

response, attacks on the objects may be less effective and more destructive

than attacks on the people themselves. For example, in WWII, attacks by the

Allies on the research centre at Peenemünde to disrupt the development of V-

2 rockets, though it was quite destructive, was not very successful – research

49 For discussion of the similar real world case involving German forces in

Afghanistan, see Crawford Identifying the Enemy, 65-6. 50 This also supplies a response to Adil Haque’s argument that the prohibition

on killing civilians is justified because we should be more cautious about

killing non-liable people than letting non-liable people die. See ‘Law and

Morality at War’, 87-9. The examples just outlined show that the relevant

tradeoff is often between killing and killing more, not between killing and

letting die. 51 Examples of this kind of reasoning are found in Schmitt ‘Deconstructing

Direct Participation in Hostilities’ Section B.

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was simply moved elsewhere. It is not clear whether it was possible to target

the researchers themselves, but doing this may have been much more

effective. And if it was effective, it would seem permissible - V-2 rockets

killed thousands of British civilians toward the end of WWII.

Similarly, recall the oil tankers case. Suppose that it was possible kill

those who were about to steal the oil tankers rather than targeting the tankers

themselves. If the tankers are in civilian areas, targeting them might cause

many civilian casualties. Targeting the civilians before they get in the tankers

might achieve the same result, but with far fewer casualties.

ii) Punishing the Righteous

A second reason against divergence is that Strict Legal Immunity prohibits

morally permissible conduct, and it warrants blaming and punishing people

for acting permissibly.

Of course, it might be argued that the LOAC makes killing non-

combatants wrong. It is not completely implausible that it does. One bad

reason for this view is the general idea that people have a general obligation

to obey the law as such. Even if there is a general obligation of this kind, it is

not important enough to make a significant difference in the case of war,

where life and death is at stake. But there might be a derivative obligation to

obey the law: an obligation to obey it because disobeying it will encourage

other people wrongly to disobey it.

It is doubtful, though, that this argument is sufficiently powerful to

support Strict Legal Immunity. It succeeds only if harm caused by breaking the

law is outweighed by the benefits of encouraging other people to abide by it.

It is an empirical question whether this is true. Given the wide range of

situations that arise in war, it is doubtful that the empirical considerations

will uniformly favour obeying the law. If not, Strict Legal Immunity commands

at least some people not to do what they are permitted or required to do, and

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it warrants punishing these people for doing what they are permitted or

required to do.

To be clear, I am not an extremist about punishing the innocent. There

are circumstances where legal prohibitions ought to be created that warrant

punishing some innocent people, for example because it is too difficult to

distinguish the guilty from the innocent.52 All I claim is that this is very hard

to justify. It is especially hard to justify in war, where the innocent who are

punished will be putting their lives at risk for the sake of others.

iii) Disincentives

Qualified Legal Immunity also creates valuable disincentives to engage in

unjust wars. A standard objection to the decision to go to war is that

politicians can ensure that people who they care little about – the relatively

poor and unqualified people who will serve on the front line – are exposed to

lethal threats, where people like them are protected.

Political leaders who are inclined to orchestrate unjust wars might be

less inclined to do so if they think that doing so makes them liable to attack.

Of course, there are countervailing pressures on those whose wars will be just

– the unjust side will think that their cause is just, and so will be more likely

to attack politicians, or those in their social and economic class. And so there

will be some disincentives to engage in just wars, which is regrettable. But

even so, the incentives might be favourable overall, because most wars are

unjust. We know that most wars are unjust for the following reason. Some

wars are fought between two unjust sides; some wars are fought between one

unjust side and one just side; but no wars are fought between two just sides.

For this reason it is plausible enough that a uniform disincentive on going to

war will be beneficial overall.

52 See Tadros Wrongs and Crimes ch.17.

39

iv) Symbolism

There is also a symbolic reason for convergence. Suppose that the distinction

between combatant and non-combatant is not in itself morally significant, and

that non-combatants, like combatants, can be liable to be killed to avert

threats they contribute to. This view not only unsettles a common view about

what it is permissible to do in war, it also unsettles a common attitude that

people have to others in war: the attitude that the deaths of non-combatants

as more horrific or regrettable or morally abhorrent than the deaths of

combatants.

For example, a common response in the UK to the war in Iraq involves

castigating political leaders for going to war because of the unnecessary loss

of life to UK military personnel. Some object to this, arguing that the large

number of civilian deaths that were caused by the war were much more

objectionable than the deaths of UK military personnel. But almost no one

objects to the loss of life of Iraqi military personnel, as though their status as

combatants made their deaths less regrettable. Recognizing that liability does

not arise because a person is a combatant might alter the problematic

attitudes that people have to unjust combatants.

XI. The Costs of Qualified Legal Immunity

What are the disadvantages of Qualified Legal Immunity when compared with

Strict Legal Immunity? Again, I lack the space for a comprehensive survey. But

I address some of the main concerns.

i) Attacks on Non-Combatants by the Unjust Side

One obvious objection to Qualified Legal Immunity is that the just and the

unjust sides in a war will equally take advantage of it. Some might conclude

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that any advantages that arise by relaxing immunity for the just side are

counterbalanced by disadvantages by relaxing it to the unjust side.

Take a simple war between two states, X and Y, where X is the just side

and Y the unjust side. Suppose that Qualified Legal Immunity was law and that

both sides believe that they have a just cause. They therefore each target non-

combatants to eliminate the threats they pose. And suppose they would not

do this were Strict Legal Immunity to be law. Whether one side or the other has

improved prospects of winning depends on the contributions that non-

combatants make to the war, how effectively they can be targeted, and so on.

But there is no general reason to think that X’s prospects of winning are

improved by Qualified Legal Immunity when compared with Strict Legal

Immunity.

One response to this problem is to attempt to ensure that Qualified Legal

Immunity affects conduct asymmetrically. For example, we might add a

further clause to Qualified Legal Immunity that permits killing non-combatants

only if the UN Security Council has authorized the war. Of course, the

Council is notoriously flawed in assessing which wars are just. It may not

authorize some just wars, and it may authorize some unjust wars. But as long

as it tends to be right, Qualified Legal Immunity would then tend to favour the

just side.

Suppose, though, that this proposal should be rejected. Qualified Legal

Immunity may have good effects even if it affects the behaviour of both the

just and the unjust side. This is for the reason that I noted earlier – that

Qualified Legal Immunity creates the opportunity for a less destructive way of

securing one’s outcome. That seems attractive whether or not one’s outcome

is just.

For example, suppose that the unjust side in a war is much more

powerful than the just side, and would win the war whether Qualified Legal

Immunity or Strict Legal Immunity was law. It is better that it wins in a swift

and less harmful way than in a more protracted way. If it is permitted to

target those developing weapons technology, for example, it will win more

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swiftly, causing less destruction. Often, Qualified Legal Immunity will not make

a difference to who wins the war, but only to how quickly they win. So there

is some reason to favour Qualified Legal Immunity even if it leads to both sides

attacking non-combatants who make significant contributions to the war.

ii) Abuse of the Rule

A further objection is that Qualified Legal Immunity is open to misapplication

or abuse. It might cause ineffective attacks on non-combatants who do not

contribute to the war effort, or to a failure to prevent the contributions made

by those who do, say because their contributions are overdetermined. There is

also a risk that some might use Qualified Legal Immunity in an attempt to

exonerate punitive or terror attacks on non-combatants.

Focus on ineffective attacks first. It is obviously bad if the just side in a

war attacks non-combatants who make no contribution to the war effort. They

are not liable to be killed, and so the number of people who are wrongly

killed increases. This is a significant disadvantage of Qualified Legal Immunity.

The risk might be thought small. Laws are typically influential only to those

who make some effort to comply with them, either because they believe them

to be valid, or to avoid sanction. Qualified Legal Immunity sets out significant

restrictions on the permission intentionally to attack non-combatants. Those

who aim to comply with the law be will likely to attack non-combatants only

if doing so gives them a significant military advantage – the use of special

forces to kill those involved in weapons development is the kind of example

where this might be satisfied.

Still, there is at least some evidence that Qualified Legal Immunity will

be abused. It might lead to an increase in targeted killing, and that might be

undesirable. The Israeli government, for example, uses the current rules on

direct participation in hostilities to legally justify targeted killings of

Palestinian militants. They may well extend this policy in response were

Qualified Legal Immunity the law. For those who are sceptical that the current

42

policy is justified, this may seem a significant cost of legal change. Of course,

there are difficult empirical questions about the policies of targeted killings

that have been implemented especially by the US, Russia, Israel and other

countries. To some extent, these killings may come to replace wars, which

might be thought in some ways desirable.

But if targeted killings of this kind are regrettable, there are other ways

of responding to the problem. The view that targeted killings that have been

carried out by Israel, the US and Russia are best regulated only by the laws of

war is at best controversial – they are not part of a war, but rather implement

a long term policy to police terrorist organisations. The law can indicate more

clearly and firmly that they fall outside of the laws of war and respond to

them with a distinct legal regime, or ensure that such killings are legal only if

they satisfy the standards of all legal regimes that apply to them, including

not only the laws of war but also International Human Rights Law.53 This

may indeed be the current legal position, with the implication that there is an

imminence requirement on the use of force that derives from the law of self-

defence.54

No doubt, it is difficult to sharply distinguish between wars on the one

hand, and conflicts between states and terrorist organizations on the other.

But given the political pressures for an overzealous response to terrorism that

have existed since 9/11, there are reasons to be cautious about extending the

legal regime that is used to govern war to the control of terrorism. The legal

response to targeted killing outside of the context of war is not well

53 This problem has been widely discussed. See, for example, M Sassòli

‘Terrorism and War’ (2006) 4 Journal of International Criminal Justice 959;

Crawford Identifying the Enemy ch.4; C Heyns, D Akande, L Hill and T

Chengeta ‘The International Law Framework Regulating the Use of Armed

Drones’ 2016) 65 International and Comparative Law Quarterly 791. 54 See Heyns, Akande, Hill and Chengeta, 800-5.

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developed, and the practice is best regulated by legal regimes beyond those

that apply to war.

If the restrictions set out in Qualified Legal Immunity prove insufficient

to prevent abuse, further conditions can be added, or procedural standards

can be adjusted, to make abuse less likely. One possibility is to lower the

standard of proof required for a conviction, or to reverse the burden of proof,

requiring those who kill unjust non-combatants to show that their conduct

was legally permitted.55 Of course, this comes with an increased risk that the

innocent will be convicted. But that risk is already inherent in the law as it

stands, which prohibits an even wider range of non-wrongful conduct.

iii) Collateral Damage

A further objection is that Qualified Legal Immunity will have bad

consequences for the application of proportionality rules in war.56 At present,

the deaths of combatants are completely discounted when applying

proportionality rules. Acts of war cannot, therefore, be legally

disproportionate because of the number of deaths to them that are caused.

Would Qualified Legal Immunity imply that the lives of non-combatants who

55 There is some confusion about the current standard of proof. Article 50(1) of

the Additional Protocol I to the Geneva Conventions indicates that in the case

of doubt, a person is to be considered a civilian. However, in the case of a

prosecution in international criminal law, the prosecution must prove beyond

reasonable doubt that the person attacked was not participating in acts of

war. See Prosecutor v Strugar (2008) Case No.IT-01-42-A, 176-9. The ICRC

suggests that the burden and standard of proof ought to be different where

the question is whether a civilian is directly participating in hostilities. For

discussion, criticizing the view of the ICRC see Schmitt ‘Deconstructing Direct

Participation in Hostilities’ 737. 56 I am grateful to Adil Haque for encouraging me to consider this.

44

make substantial contributions to the war effort also count for nothing in

proportionality judgements?

The relationship between liability and proportionality, both in morality

and law, is too complex for me to consider it in detail here. My own view is

that completely discounting the lives of combatants in assessing

proportionality is mistaken, and can lead war to be much more destructive

than it needs to be.57 Here, though, I only note Qualified Legal Immunity leaves

all options open. It says nothing about liability, so it does not imply that the

lives of non-combatants who make substantial contributions to the war effort

are discounted in this way.

iv) An Immunity Culture

Perhaps the strongest argument against Qualified Legal Immunity is that it

erodes a growing consensus concerning non-combatant immunity. It might be

a good thing if a small exception was created. But there is a risk that in

creating such an exception will have a negative effect on the general culture

that treats the killing of non-combatants as abhorrent. It is generally easier to

get a consensus around a very simple standard, like Strict Legal Immunity,

than a more complex standard like Qualified Legal Immunity. The more

complex standard might lead to the development of further unwarranted

exceptions in the law.

It is very difficult to predict what the wider effects of Qualified Legal

Immunity would be, but I doubt that they would be as dramatic as the

objection claims. The qualification is relatively modest. If the risk of

disrupting the effects of the laws of war is too great perhaps Qualified Legal

Immunity ought to be created only once a more mature legal culture was

developed, which could ensure that jurisprudence around the exception was

57 For related discussion, see V Tadros ‘Orwell’s Battle with Brittain: Vicarious

Liability for Unjust Aggression’ (2014) 42 Philosophy and Public Affairs 42.

45

suitably constrained. If so, Qualified Legal Immunity might be a longer-term

aim.

Conclusion

Despite the fact that recent philosophical work on the war has led many

people to radically revise their views about the morality of war, they have not

led many people to radically revise their views about the laws of war. I have

offered a somewhat cautious defence of a more revisionist view. Many see

great dangers in changing the laws of war, but there are also dangers in

retaining the status quo. When the devil we know is so destructive, it might be

time to switch.