If killing is wrong, how can going to war be justified? Is it always wrong to kill civilians? If a Nazi soldier were billeted in your home, should you respond when he greets you? Philosopher Cécile Fabre chooses Five Books that help explore the profound ethical dilemmas of war.

How did you first get interested in writing about war?

I first got interested in war as a student of history in high school, in France. The study of war in general, and the two World Wars in particular, was absolutely central to my curriculum. When I started studying philosophy, I wasn’t writing about war initially, but I came to realise over the years that I was getting more and more interested in the ethics of war. I also came to the realisation that, if I were to write about war, I could combine my historical interest in war with my philosophical interest in it as well. So that’s how it started.

How many books have you written about war?

I have written two: one is called Cosmopolitan War and the sequel is Cosmopolitan Peace.

What’s the connection between war and cosmopolitanism?

I’m interested in the following question: suppose that as a cosmopolitan, you believe that political and national borders are largely irrelevant from a moral point of view. That is to say, they are irrelevant to which fundamental rights we have, and which duties we have to fulfil. If you believe that, then what happens to the morality of war? It’s an interesting question because we tend to think of war as quintessentially a matter of ‘us,’ the French, the British, against ‘them,’ the Germans, the Soviets; but of course, as a cosmopolitan I’m bound to be uneasy about characterising war in this very dichotomous way. So that’s what got me interested in that question.

Is this cosmopolitanism close to humanism, in that it focuses on humanity in general?

Yes, very much so. The view is that every single human being, wherever they are located in the world, irrespective of their membership in this or that political community, matters, and matters equally. That’s the key tenet of cosmopolitanism, and so construed, it is very close to, you might even argue identical with, humanism.

Read 1 War and Peace (Book) by Leo Tolstoy Read

The first book you’ve chosen is Tolstoy’s War and Peace (1869), obviously an amazing book. Why did you choose it specifically in relation to war?

I chose it, first of all, not exclusively in relation to war. It happens to be one of my three favourite novels, so I wasn’t going to pass up the opportunity to talk about it. I am also interested in it in relation to war for a number of reasons, some of which have to do with the fact that I’m French.

First of all, Tolstoy is read by the French very widely, perhaps more widely than by the British, as far as I can make out. Tolstoy, of course, knew French very well: strictly speaking French was his mother tongue. Interestingly, the first paragraph of the novel is in French. I was reading the other day that two per cent of the novel is actually written in French. The Russian aristocracy spoke in French, and, in fact, Tolstoy learnt Russian only because his nanny spoke to him in Russian: his parents spoke to him in French. What’s very interesting about the novel is that, at the beginning, there is quite a lot of French, but, as the novel progresses, as the French become clearly and increasingly identified with the enemy, and as the novel re-centres itself, as it were, around the particular ideal of Russianness, then there is less French, and the aristocrats more and more, even between themselves, speak Russian. So in 1812, 1813, 1815 they speak Russian, unless they don’t want to be understood by their children. But at the beginning of the novel, in 1805, all that they speak is French. Tolstoy’s choice of the language in which his characters speak is indicative of the ways in which the Napoleonic wars, he argues, have changed Russian society, or rather the Russian aristocracy, because he doesn’t write very well about non-aristocrats.

Above and behind the language, Tolstoy, in the novel, looks at the way in which the Napoleonic wars have influenced and shaped the life and destiny of five aristocratic families. As the novel starts, those aristocratic families display a particular kind of culture, a particular kind of sensibility that many people, rightly or wrongly, associate with French culture. When I first read the book a long, long time ago, I was very sensitive to that.

“War is the product of millions of individual decisions which collide with each other, which are the product of pure chance and luck.”

As a French person, it’s particularly interesting to read about the impact of the Napoleonic wars on a society other than French society. I also studied Russian at school, and War and Peace is, in fact, the first Russian novel I ever read, at first in translation, and then in Russian. It spoke to me, and it still speaks to me in that way. Through my knowledge of the language I can hear the rhythm of the sentences, and so on.

Of course, when I started thinking and writing about war as a scholar, I became more aware of other features of the book in relation to war which I wasn’t really aware of before. To give you a few examples, we tend to talk quite a lot about the ‘fog of war,’ the fog that makes it impossible for soldiers really to make the kind of decisions that they ought to make, either strategically or ethically. There are a number of relevant scenes in the novel, and one in particular, which takes place in 1805, in the Battle of Austerlitz. One of the main characters of the book, Nikolai Rostov, is lost on the battlefield in the fog of war. Tolstoy shows, with extraordinary power and clarity, precisely how unclear things are. Rostov doesn’t know where he is, he doesn’t know whether the shadows he sees moving are Russian soldiers, or French soldiers about to kill him. It’s one of the most vivid literary passages I’ve ever read about war. It describes the sort of conditions under which soldiers, more often than not, have to operate, when they simply do not know what it is that they’re doing. So that’s one literary example, an illustration of the view that philosophers try to articulate: given that a soldier has to operate under those sorts of conditions, what moral expectations can we reasonably form of that particular soldier?

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The book also talks about the losses of war, the loss of life. One of the main male characters, Andrei Bolkonsky, dies in war in 1812. In the latter parts of the novel, we see the impact that his death has on his loved ones. There are other characters who die, less prominent characters, and again, Tolstoy shows very well the impact that their deaths have on those who survive. Survivor guilt is at play there, as well as the grief of a mother who has lost one of her two sons ­– not just the grief actually, but the grief-induced depression that can take hold of someone when they have lost a child. Again, we know that, but Tolstoy describes it with profound compassion, humanity and tenderness even, for his characters and for his fellow human beings who have gone through this in real life.

The final point I want to make about the novel is that it is followed by an appendix which Tolstoy wrote when the novel was finally finished and published in extenso in 1869. One of the key questions that Tolstoy asks in the appendix is the central question of War and Peace: how can we explain the fact that, on orders, millions of people go out and kill one another, when they know that killing another human being is morally wrong? His answer to this question is that we should dispense with the view that they so act because of the genius of one person: Napoleon, for example, or because of the shrewd military brain of a general, such as the Russian General Kutozov.

We can’t explain the phenomenon, Tolstoy says, other than by realising that war is the product of millions of individual decisions which collide with each other, which are the product of pure chance and luck. What Tolstoy concludes is that we are deluding ourselves if we think that soldiers act freely when they decide to go: they don’t. That’s one point where, according to Tolstoy, we don’t have free will: the point at which we have to make a decision whether or not to go to fight. He says it’s inevitable that we shall all follow our regiments: we do not have freedom of will in those cases. That’s a question that philosophers of war have all asked themselves relentlessly: are soldiers really free to act, or not to act, in such ways?

Read 2 All quiet on the Western Front by Erich Maria Remarque Read

Which book is your second choice?

All Quiet on the Western Front (1929), by Erich Maria Remarque. This is a landmark novel about war in general, and the First World War in particular. Remarque was a German writer who subsequently was exiled from Nazi Germany to the United States. He had quite an extraordinary life. He fought in the First World War, and the book, which is written in the first person, is largely autobiographical. It’s a remarkable novel which I chose for mostly two reasons. The first one is that, better than any novel or indeed first-hand account I’ve read about war, it shows what’s animal and animalistic about war. The second reason I chose it is because it also claims that, even in the middle of such horrors as were experienced in the trenches, there was always a spark of hope, a spark of life, without which you can’t go on.

“There is a scene where the soldiers get very distressed by the sound of horses which have been injured and which are screaming in agony”

So let me start with the animal/animalistic dimension of war. Animals are very present in the book. For example, there is a scene where the soldiers get very distressed by the sound of horses which have been injured and which are screaming in agony, and they are so distressed that one of them in particular—a farmer in civilian life—can’t bear it anymore. He leaves the trench at great danger to himself, and goes off to kill the horses to alleviate their suffering. What’s interesting in that scene is that as much as the deaths of the fellow human beings was something that the soldiers were slowly becoming, not indifferent about, but inured from, the suffering of those animals somehow was unbearable, as if causing such suffering to animals, the innocent par excellence, really is a mark of profound inhumanity.

In other scenes, the narrator tells the story of the extent to which those soldiers were being dehumanised by the conditions under which they had to operate. To my mind, one of the most powerful passages illustrating that point is one where he describes a sleepless night that they’re all spending in the dugout, sleepless not just because of the cold and the mud, but because the rats have turned up, having smelled leftovers of food. As a result, the soldiers spend the entire night defending themselves from the rats. The description of the scene ends with the sentence ‘we were about to set ourselves upon each other.’ What this scene describes is that in just the same way as the rats viciously fought each other to get the last bit of the breadcrumbs, the soldiers were so exasperated, out of their mind exasperated with having to fight the rats, that they almost became like the rats themselves. That is, again, a profoundly evocative description of what fighting under those claustrophobic, constrained conditions can do to people, to human beings.

“He knows that his pleasure at a beautiful landscape, at the smell of good food, will forever be coloured by what the landscape looked like in the trenches, by the food that was cooked in the trenches”

The other reason I chose the book is because in the middle of this horror, there is always, as I’ve mentioned, a spark of hope, and also elements of beauty, which is slightly different. Let me start with this idea that even in the horror you can find beauty. In fact, more precisely, you can find beauty in scenes which, actually, in the ordinary course of events, you wouldn’t find beautiful. One of the scenes where the narrator describes joy and happiness the most vividly is one where he and his friends have managed to find a place where there are proper latrines, and the latrines are outdoors. So they all sit down and defecate, basically, in the company of each other. The narrator says that in the open air, listening to the birds, away from the front, the soldiers found enormous joy and tranquillity in this very simple act of sitting and defecating peacefully together. Now, normally we don’t think of this particular act as being a beautiful act, but what’s remarkable is that precisely because of the conditions of war, that act, that very animalistic act, has become something to be treasured. The inference I think we’re meant to draw is that only war will enable you to tap into this.

“I’ve always enjoyed reading fiction, so that’s part of it, but I think I also do it almost as a matter of professional duty”

That said, I think the most important lesson of the book is the spark of hope in the middle of horror. That’s how the book almost ends. I want to read a paragraph which I think is wonderful. So, it’s October 1918, and there are rumours that an armistice is imminent. The character is feeling deeply sad and melancholy, because he realises that when the war is over, as it soon will be, they will all go back to their former life, except that their former life is gone forever, and no one, he says, will understand them. This is what he concludes, nevertheless:

‘But perhaps all these thoughts of mine are just melancholy and confusion, which will be blown away like dust when I am standing underneath the poplars once again, and listening to the rustle of their leaves. It cannot have vanished entirely, that tenderness that troubles our blood, the uncertainty, the worry, all the things to come, the thousand faces of the future, the music of dreams and books, the rustling and the idea of women. All this cannot have collapsed in the shelling, the despair and the army brothels.’

That’s not the last paragraph of the book. The last paragraph of the book describes, from a third-person perspective, the soldier, the narrator, being found dead in October 1918, and the last paragraph says: ‘He had sunk forwards and was lying on the ground as if asleep. When they turned him over, you could see that he could not have suffered long – his face wore an expression that was so composed that it looked as if he was almost happy that it had turned out that way.’ So just before dying, that soldier, with whom we have lived for the 200 pages of the book, has come to the realisation that he still has that hope to which he can cling, that it cannot all have vanished entirely. He dies, that’s the tragedy of it, but I do think that Remarque is trying to tell us that even then, even in something so horrible as trench warfare, it was possible for some, until the very end, to keep a spark of humanity within them.

Couldn’t there be a degree of irony there, the sense that he is foolishly thinking things would go back to normal when, as we know psychologically, people who have been through terrible things in war don’t ever get back, straightforwardly, to normal?

I don’t think the character, the narrator, thinks that things will go back to normal. I think he’s really aware that the idea of women will not be the idea of women that he would have had had he not been to war. He knows that his pleasure at a beautiful landscape, at the smell of good food, will forever be coloured by what the landscape looked like in the trenches, by the food that was cooked in the trenches. What the narrator is saying, I think, and what Remarque through him is saying, is that even if you are forever altered by the experience of war, it remains possible, at the point at which war is at its most awful, to hope that you will not be indifferent, that you will not have lost your humanity to such an extent that it will no longer matter to you, that you might find a landscape beautiful, that you might desire a woman, and so on and so forth. I think that’s what the novel is trying to tell us in its concluding pages.

Now this might be an unfair question, but I’m interested. These are two works of the imagination, and they serve a very useful function for people who haven’t been through war, apart from anything else. Have you yourself ever been in a war zone?

No, I haven’t been in a warzone myself. I think it’s a very good question that I raise quite a lot with the soldiers I have the opportunity to talk to once in a while. I always feel that, as a philosopher, I somehow don’t have the right to moralise about war because not only do I have no idea of what it’s about, but I fervently hope that I will never have an idea of what it’s about. Now, invariably, those soldiers, and I hope that they’re not just being polite, respond to me that not having first-hand experience of war doesn’t necessarily disqualify me from being able to talk about it. I hope they’re right. But one of the reasons why I keep reading fiction, literary works about war, is as a partial substitute, if you will, for actually experiencing it myself. I don’t find in even the best philosophy books that I’ve read about war, two of which we are going to talk about presently, enough descriptive, evocative content to give me a sense of what it can be like, actually to be told at gunpoint that you have to go over the trenches, failing which you’ll be shot by your superior officer, what it can be like to lose control of your bowels as you do that. To even begin to get a sense of what it might be like, I have to read literature. I’ve always enjoyed reading fiction, so that’s part of it, but I think I also do it almost as a matter of professional duty. I can’t go to war, I don’t want to go to war, and the very least that I can do is actually read those works which, even if it’s not obvious in what I write, nevertheless inform the way I write.

Read 3 Le silence de la mer by Vercors Read

So, the third book is also a novel. This is in French, is there also an English translation?

The third book is a book which in French is called Le Silence de la mer (1942). In English, it is translated as The Silence of the Sea. It was written by a French journalist, essay-writer and illustrator who had joined the Résistance during the Second World War, and who, in fact, co-founded the publishing house, Les Éditions de Minuit, the Midnight Publishers. That publishing house operated within the Résistance in a clandestine way throughout the war. This particular book was its very first publication. This publisher still exists: it is one of the best known and most prestigious in France.

The book describes the ways in which the narrator, who is an elderly man, and his niece, are affected by the presence in the house, for six months, of a German officer who has been billeted there.

I’ll say a bit more about the novel, but there is an interesting fact about it. It was translated into English and turned into a television play; that television play was actually shown by the BBC on the 7th June 1946, the day the BBC television resumed its broadcasts after the Second World War; they had stopped in 1939. I managed to find the original schedule for that day, and I can tell you that it was shown at ten past nine in the evening. I would love to find the footage, and in fact I will write to the BBC to ask whether it’s possible.

“Britain…has not known an occupation for many, many centuries….whereas France was occupied, by the Germans, on three different occasions”

The book is not very well known in Britain, but it’s extremely well known in France. The reason why it’s not very well known in Britain is the obvious one that Britain, apart from the Channel Islands, has not known an occupation for many, many centuries, not since the Normans; whereas France was occupied, by the Germans, on three different occasions: 1870, northern France during the First World War, and most of the country during the Second World War (with Italian forces occupying the South East). The experience of occupation is absolutely central to contemporary French culture. I also think, as a French person residing in Britain—I’ve lived in Britain for most of my adult life—that there are very important differences between the ways the French perceive the Second World War, and the ways the British perceive it. To my mind, the single most important factor that explains those differences is the occupation.

As you can see, I have semi-autobiographical reasons for choosing the book, in that broad narrative of being French and living in Britain. I have an even closer, more local autobiographical reason, which is that my maternal grandmother and her family, for four years, between 1940 and 1944, had to share their house with five German soldiers at any one time, two of whom stayed for about two and a half years. Now that house, my family’s house, had only one kitchen, one staircase, one entrance door. The soldiers were billeted on the top floor, but they had no choice but to go in through the main door to go up to their bedrooms. So, when I first read the book, that spoke to me.

“Occupation, particularly this kind of occupation where the enemy lives in such close proximity with the occupied population, is one of the worst dilemmatic ways in which a war can be conducted”

But I also think that the book should have profound interest for anyone who is thinking about war—above and beyond those not particularly interesting autobiographical details—which is that we think of war as a theatre where the actors of the war are constantly confronted with moral dilemmas. But occupation, particularly this kind of occupation where the enemy lives in such close proximity with the occupied population, is one of the worst dilemmatic ways in which a war can be conducted. The novel shows that very well. It’s dilemmatic at the level of very simple, but very concrete, daily decisions.

So, we have this narrator, who lives with his niece, we don’t know why they live together, it doesn’t really matter. One day, there’s a knock on the door and this very good-looking, extremely polite, French-speaking, very cultured German officer presents himself. He’s been billeted in the house.

“The facts of the occupation in the Channel Islands are not very well known in Britain either, which I think is regrettable”

The first decision that they have to make is whether to allow him to use the main entrance as a way into the house – or whether to ask him to use the kitchen entrance. He actually offers to use the kitchen entrance, he’s sensitive enough to the difficulty to make that offer. The narrator decides, without saying it explicitly, that he’s not going to lock the main entrance. This is where it gets interesting. There are two reasons behind his decision: first, he says that he doesn’t want the presence of that officer to change anything at all of their daily life and the organisation of their household. But he also says, explicitly, that he could never bear to give offence to another human being, even if that other human being happens to be an enemy. Already they have to make that decision, knowing that by allowing the officer to come in through the main door, which is the door that they use, they might be described by him and by other people in the neighbourhood, as being very friendly to the soldier. That might be problematic.

“We learn that the niece, despite herself, falls in love with the German officer, and he falls in love with her”

The second decision they have to make is whether to talk to him. They never do, until the very, very end. Only at the very end do they talk to him, and then only very briefly. For six months, almost every night, he comes into the living room, he warms himself by the fire, he shares details about his life, he shares his views of a dream of an alliance between Nazi Germany and cultured France. They never respond, not a single time. They don’t look at him, they don’t show him that they are aware of his presence in any way. That, too, is very interesting. They had to decide, in fact in the same way as my family had to decide, whether to say ‘hello,’ whether to say ‘come in,’ whether to say ‘goodbye,’ whether to engage in conversation. They decide not to. I was always very struck by this. That’s why the book is called Le Silence de la mer: you remain silent, but, underneath, the sea is bubbling with suppressed feelings of anger, of sympathy, of compassion, of love. We learn that the niece, despite herself, falls in love with the German officer, and he falls in love with her. That’s never acknowledged explicitly.

I’ve always found this novel very powerful because it shows how important, and difficult, morally speaking, those decisions are, which we all have to make under those circumstances: whether or not we should treat the enemy—and in this instance it’s an enemy who lives with you—mostly as an enemy, mostly as a human being, or as a mixture of both, where we can’t separate out anymore that strand in him which is the enemy, and that strand in him which is the human being. That’s why I chose the book.

Is there a reason you’ve mostly referred to the French edition?

No, no there isn’t. What you might have detected is the fact that I don’t know anyone who’s ever heard of it in English. I think the reason why that is, is that the British and the Americans have not really been subjected to military occupation in living memory. They have occupied, but they’ve not been occupied, except of course, for the Channel Islands – but the facts of the occupation in the Channel Islands are not very well known in Britain either, which I think is regrettable.

Read 4 Just and Unjust Wars: A Moral Argument With Historical Illustrations by Michael Walzer Read

The fourth book is a very famous book, perhaps the most famous recent book on the philosophy of war.

That’s right. It’s Michael Walzer’s Just and Unjust Wars, which was published in 1977. This is the most famous of the twentieth century works on the philosophy of war. It’s a fantastic book for a number of reasons. It should be read, not just by people who are interested in war, but by all philosophers: it combines really interesting philosophical arguments with historical cases, and that’s one of the things I really love, and that most people love, about it: it’s a wonderful blend of the philosophical and the historical.

“The 1970s witnessed a revival of normative political philosophy”

It’s an important book in the history of moral and political philosophy, as well. For a very long time, between roughly J. S. Mill in the middle on the nineteenth century, to the 1970s, there was really very little by way of normative work in English in moral and political philosophy, particularly in political philosophy. The 1970s witnessed a revival of normative political philosophy, most famously, Rawls’s Theory of Justice was published in 1971. The first issue of Philosophy and Public Affairs, which is one of the two main journals in political philosophy, came out in 1971. Then we had Nozick’s Anarchy, State and Utopia, which is a response to Rawls, in 1974; and then came Walzer’s book in 1977. So it’s part of that ensemble of works which put the normative, the question of how we ought to behave or not to behave towards each other, particularly as political agents, very firmly on the table. It’s also a book which, though it came out at the end of the Vietnam War, was obviously very influenced and shaped by it. These are some of the reasons why I’ve chosen it.

“Walzer talks about what a soldier is to do when he’s faced with an enemy soldier who’s asleep, or naked, taking a bath, or having a cigarette”

I should say that I disagree with many of the claims that Walzer makes in the book. He is known in political philosophy as a broadly communitarian political philosopher, someone who believes that the community, in general, and communal understandings and beliefs in particular, which agents generate, have a moral status, a moral value, that is not reducible to the moral status and value of individual members of those communities. That leads Walzer to make claims which, in my view—and I’m not the only one to think this—seem to be very problematic. For example, on the topic of when humanitarian intervention in the affairs of another state is justified, Walzer has a very narrow and restricted account of justification for intervention. He shows deference towards communal understandings and traditions, some of which we ought to reject precisely because they are not sufficiently sensitive to the interests of individuals. For Walzer, a people has to rise itself before outside intervention is justified, and it’s never clear how homogenous or not his conception of ‘a people’ is. We might want to say to him, ‘Well, the people as a whole don’t rise, but we have a minority here, which is severely persecuted, which can’t rise up on its own. Why should we give deference to the communal understandings of the majority, vis-à-vis this particular minority?’

But the single most important point of disagreement I have with Walzer has to do with the role and status of soldiers. Walzer articulates the view, which is central to contemporary laws of war, that once the war has started, irrespective of the values for which they fight and kill, soldiers on opposite sides of the conflict are morally on a par with each other. So, for example, on the plausible assumption that Germany wrongfully invaded Poland in 1939, on the plausible assumption that German soldiers were killing Polish soldiers in pursuit of an unjust aggression, and that Polish soldiers were rightfully defending their country, even on those assumptions, for Walzer, a German soldier was as entitled to kill a Polish soldier in his own defence, as a Polish soldier was entitled to kill a German soldier in his own defence.

“Walzer takes the view that we may not, except under conditions of supreme emergency, deliberately target civilians”

Walzer gives several reasons in support of the claim that morally there is no difference between the German soldier and the Polish soldier. Those reasons are reasons which I, and many others, reject. The most important reason is that, for Walzer, a soldier is nothing but an instrument of his or her state in a foreign policy, so you can’t charge a soldier, an ordinary individual soldier, with the crime of aggression. That crime is not committed by the soldier, it’s committed by the soldier’s leaders. It’s appropriate to put Goering on trial at Nuremberg, but it’s not appropriate to put on trial, at Nuremberg, for the crime of aggression, the ordinary soldiers without whom the aggression would not have taken place. I disagree with that. The fifth book that we’re going to talk about gives a number of reasons as to why we should disagree with Walzer. But before I get on to that book, I just want to say a bit more about why Just and Unjust Wars, for all its argumentative flaws, is remarkable.

It’s an extraordinarily compassionate, humane book. There are passages in the book where Walzer talks about soldiers in ways which I find really moving. One passage always comes to my mind when I think about it, a passage where, by using George Orwell’s description of an incident that happened to him whilst he was fighting in Catalonia, Walzer talks about what a soldier is to do when he’s faced with an enemy soldier who’s asleep, or naked, taking a bath, or having a cigarette. The question is: while that soldier is not threatening me, he’s not armed, should I kill him? May I kill him, nonetheless? Some people take the view that you can kill him, other people take the view that you cannot. But what I really love about this passage is that Walzer manages to convey how much of a dilemma it is, precisely because there is a sense in which that soldier, who is naked, or asleep, appears to us in his humanity.

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That’s one of the most important lessons of the book: when we think about wars, whether as philosophers, or soldiers engaged in that war, or as citizens about to decide whether to mandate a government to go to war, we should never lose sight of the humanity of our enemy, even if we end up killing that enemy; we should never forget that we are killing a human being, not a rat, not a horse, not a robot, but a human being. There are very few books of philosophy which are so replete and redolent with that sense of humane compassion, but that one really is, and it’s admirable for that.

Read 5 Killing in War by Jeff McMahan Read

Now, Walzer’s book, and Jeff McMahan’s Killing in War (2009), which is your final choice, are both books on the philosophy of war, both deeply influenced by this tradition of ‘just war theory.’ Perhaps you could say a little bit about that tradition.

That’s right, both books address the following perennial question: on the plausible assumption that it’s prima facie wrong to kill another human being—that what we have to justify is the act of killing rather than the decision not to kill—under what conditions, and why, is killing ever justified? War, of course, is the paradigmatic social phenomenon where killing takes place on a very large scale.

That moral question is a very ancient question: we find it addressed in the Bible, in some of the most ancient Chinese writings, in the Qur’an, we find it in Cicero, Augustine, and Aquinas, in fact throughout the history of moral and political thought. Just war theories, in a nutshell, claim that we are justified in going to war only if we meet a certain number of conditions. We have to have a just cause for going to war, the war must be proportionate, that is to say the harms it brings about must not outweigh the good that it causes, it must be the option of last resort, and we must not deliberately target innocent civilians or non-combatants (the two are not co-extensive categories).

“To say, as he does, that there are non-combatants whom traditionally we think should not be killed, but in fact may be killed, is a very brave thing to do”

Both Walzer and McMahan address that last point. Walzer takes the view that we may not, except under conditions of supreme emergency, deliberately target civilians. We may, however, target enemy soldiers, and we may do so in our own defence even if, in so acting, we further an unjust cause, for example a war of unjust aggression. Now, McMahan very strongly disagrees with that. He is at the forefront of a movement which is sometimes called revisionism, about war—or the neo-classical understanding of war—a movement which says that whether soldiers are permitted to kill other soldiers partly depends on whether they are killing in pursuit of a just or unjust cause. If we go back to the example I gave earlier of Germany’s invasion of Poland, according to McMahan and the other revisionists, of whom I am one, precisely because ex hypothesi the German soldier kills a Polish soldier in defence of an unjust cause, that German soldier is not morally permitted to kill the Polish soldier, even when the Polish soldier starts shooting at him. What he must do is surrender.

But it’s unrealistic to expect a soldier being shot at not to act in self-defence, in that context.

A lot of people will take that view. There are several responses to this. One response consists of saying that if you have the option of surrendering then that’s what you should do. If you don’t have the option of surrendering—if the choice is between allowing yourself to die on the one hand, and killing someone whom we may well agree you ought not to kill because he’s acting in rightful defence on the other hand—then you ought to allow yourself to die.

There are two contexts in which we might be prepared to hold that view. The first is a context of violence outside the context of war. Imagine a bank robbery, and the robber is armed. Now, suppose that as he starts shooting, the police turn up and start shooting at him. At this particular point, his life is under threat. He has two options. Suppose that things have got to the point where if he does show he wants to surrender, he’s not going to be believed. He has two options. He can either protect his life by killing the police officer who’s shooting at him, and that will give him enough time to make his escape; or he can not shoot back, knowing that he will die. A lot of people would say that in this particular case, he ought not to kill the police officer. Now, my question, and the question that McMahan asks as well, is this: what’s the difference between this particular case, and the case of soldiers? The norms that govern the use of violence in war are not sui generis to war: they are the same as the norms that govern the use of violence outside war.

“I describe to my students a variation on the case: you have a choice between saving your compatriot on the one hand, and a distant stranger on the other hand. Everything else is equal”

The second scenario where we might want to say, as you do, that we can’t expect someone whose life is under threat not to shoot back, is actually a case drawn from war. That’s the case where a soldier starts shooting at initially defenceless, unarmed civilians. We all agree that he may not do that: in law it’s a war crime, it’s as simple as that. Now, suppose that one of those civilians finds a gun, and starts shooting back. Take, for example, the case of the Warsaw ghetto uprising. Do we really want to say that the Nazi SS soldiers who were defending their lives from the leaders, the fighters of the uprising, were entitled to shoot back? I would say no, they were not. This is a case where initially defenceless civilians suddenly find themselves in a position to defend their lives. Why is it that at this particular point, their tormenters, their attackers, are entitled to give priority to their own life? I don’t think they are.

Isn’t the right to self-defence basic? Thomas Hobbes argued that you’re allowed to fight the executioner as he tries to string you up. It seems to be such a basic human response that you have. If you’ve got any moral rights at all, it’s a right to defend your continuing existence.

Yes, but again I think there are many contexts in which we would not hold that to be true. Imagine a woman who is being raped: she starts defending herself and it becomes clear that she will manage to kill her rapist unless he kills her. It’s not clear, to me, that he’s morally entitled to kill her in this particular case. A choice has to be made about who is going to bear the cost of dying. Why should the person who is completely innocent of wrongdoing, up until the point at which that choice has to be made, be the one to bear the cost of dying? You might say there is a sense in which we can excuse the wrongdoer who so acts, but to say that you have an excuse for so acting is not the same as to say that you are justified in so acting.

The real life example of this is a Croat, Dražen Erdemović, who entered the fighting with the Bosnian Serbs, in Bosnia. He actually handed himself over to the prosecuting authorities for his part in a massacre in which hundreds of civilians died. He was put on trial by the International Criminal Tribunal for the former Yugoslavia. His defence was duress: he argued that his commanding officer had told him that unless he shot at those defenceless civilians, he would be killed alongside them. Now the court, very interestingly, did not dispute the fact; the court agreed that he had been put under such duress. But it also argued, that this, at best, provided him with an excuse for acting as he did, but not with a justification for doing so. The duress defence served to mitigate his sentence, but he did still have to serve a sentence. That, I think, is how we should construe those cases.

And that’s Jeff McMahan’s position as well?

There are many subtle moves in the argument on this particular point, but that, in effect, is how I understand Jeff McMahan’s position. There are another two things he says which have been very important and influential. One has to do with non-combatants. It follows, from his account, that non-combatants are not always as immune from being killed as tradition has tended to think. If what makes you liable to being killed is the contribution that you make to an unjust war, then, insofar as, as a non-combatant, you too might end up making a significant contribution to the war, then you are liable to being killed. The easiest example to illustrate this is of the civilian leader who orders the army into war. But there are other examples, such as the case of the industrialists in Nazi Germany—I. G. Farben being the clearest example, Krupp being another—whose leaders were put on trial for participation in the crimes of aggression and genocide. There are other very, very tricky cases. What about the journalist who incites racial hatred? I would say that the journalists from Libre des Mille Collines in Rwanda, who broadcast heinous messages of hatred towards the Tutsis, likening them to cockroaches who had to be killed, were legitimate targets. Then you have to start thinking about the case of citizens who vote in favour of the war, and who pay for it. That’s where it becomes very, very difficult.

Also, the citizens who didn’t vote in that direction. They’re still citizens of the country: are they part of the group liability?

McMahan is very wary of group liability, as I am. In my case it’s connected with cosmopolitanism: it’s the view that every single human being matters, irrespective of group membership, so by implication, group liability is worrisome because it makes you vulnerable to burdens, liable to burdens, just by virtue of your membership in a particular group, and not by virtue of what you actually did.

Could you just say a bit more about why you think Jeff McMahan’s book is such a good one?

It’s a great book because it’s not very long but it manages to deploy a very powerful thesis. It rejects the thesis that soldiers are morally on a par by putting forward its own account of when soldiers, and indeed non-soldiers, may permissibly kill in war. It does so with extraordinary clarity and analytical rigor. In the course of defending that view, it makes interesting points about non-combatants. It’s also full of insights that just war theorists are still mulling over, for example to do with various conceptions of proportionality in war. It is also unflinchingly honest. To say, as he does, that there are non-combatants whom traditionally we think should not be killed, but in fact may be killed, is a very brave thing to do. In fact, he has come under fairly sustained attack for saying this. I admire philosophers who are willing to go, with relentless scrutiny, where their argument will take them, and who don’t want to evade the most controversial implications of their argument by fudging the issue. That’s why I think it’s a great book.

One last question. Underpinning your view and Jeff McMahan’s, and the views you’re sympathetic to, is this notion of every human being counting equally, the cosmopolitan premise, as it were. Now, sadly, that’s not a widely held premise. A lot of people have group devotions, whether they’re national, racial, village or football team-based. Tribalism is an extremely common human phenomenon. How do you get to a position of recognising common humanity?

You can only do that incrementally by—when the opportunity presents itself—really pushing people to articulate how far they are willing to go with this. One of my favourite strategies when I teach that material is to present students with William Godwin’s very famous burning building example. In Godwin’s case you have to choose between rescuing the chambermaid on the one hand, and Archbishop Fénelon on the other. I describe to my students a variation on the case: you have a choice between saving your compatriot on the one hand, and a distant stranger on the other hand. Everything else is equal: they are the same age, you don’t know either of them personally. It’s interesting that people who, until you present them with this very stark choice, would say exactly this, that we have nationalistic urges, and so on. At that particular point, far fewer people than you might think will say that they are morally entitled to save their compatriot, just purely on the basis that he’s (or she’s) a compatriot. When you push people, those affiliations are, perhaps, less deeply entrenched than we might think. Admittedly, I’m in an optimistic mood today, if you had caught me on another day I might have said, much more pessimistically, that we can only hope that, bit by bit, people will somehow get convinced of the truth of cosmopolitanism, but that really it’s a vain hope. I sometimes think it is a vain hope. Look at the responses to the refugee crisis. Today, in my optimistic mood, I’ll say there are signs that criteria for exclusion are no longer adhered to as strongly as they would have been before. As a cosmopolitan, as a humanist, I welcome that.