Thinking the unthinkable about the existential weapon

While still coming to terms with the utter devastation of two world wars within a generation, the postwar writers that would go on to become known as ‘the existentialists’ were shocked into almost instant reflection on the destructive power of the atom bomb. Albert Camus wrote that ‘Before the terrifying prospects now available to humanity, we see even more clearly that peace is the only goal worth struggling for.’Footnote ¹⁸ He spoke of the writers born at the beginning of the First World War, who had survived the Second World War, and now ‘must today rear their sons and create their works in a world threatened by nuclear destruction. Nobody, I think, can ask them to be optimists.’Footnote ¹⁹ Other thinkers associated with the existentialist tradition reflected on the advent of nuclear weapons in similar terms. Karl Jaspers, for example, remarked that ‘The possible reality which we must henceforth reckon with – and reckon with, at the increasing pace of developments, in the near future – is no longer a fictitious end of the world. It is no world’s end at all, but the extinction of life on the surface of the planet.’Footnote ²⁰ Continental existentialism was exported to other parts of the world, in part through the internationalism and activism of specific figures including Camus, Beauvoir, and Sartre. This included Japan and the generation of Japanese writers and philosophers making sense of the human and societal devastation left in the wake of the American nuclear attacks on Hiroshima and Nagasaki in 1945. Sartre in particular was a prominent influence on those like Ōe Kenzaburō, who both championed the ‘atomic bomb literature’ of postwar Japan in literary outlets but also used the development of hibakusha (survivors of the atomic bombings) culture to reflect on questions of existence, authenticity, and shame.Footnote ²¹

More broadly, in the decades that followed the zenith of its popularity, existentialism has influenced the writings of a range of commentators on the human condition in the nuclear age. Kelvin Mason, for example, writes that

Similarly, one of the most widely read authors on the issue of nuclear disarmament, Jonathan Schell, observed in his 1982 best seller, The Fate of the Earth that

In this view, the Cold War nuclear arms race was allowed to take hold due to the complacency of populations who were able to dissociate themselves from the everyday and real experience of the threat of annihilation. To openly and regularly discuss nuclear dangers became an extraordinary act while living ‘on the edge of extinction’ became perfectly normal and barely worth mentioning. For Schell, ‘[I]t was not unless one lifted one’s gaze from all the allegedly normal events occurring before one’s eyes and looked at the executioner’s sword hanging over everyone’s head that the normality was revealed as a sort of mass insanity.’Footnote ²⁴ Just as Sartre urged us to eschew ‘bad faith’ and the ‘suspension of judgement’ in our everyday existence,Footnote ²⁵ Schell counselled engaging art and imagination in order to join even the likes of Herman Khan in ‘thinking about the unthinkable’.Footnote ²⁶ A mid-1980s reflection on the ongoing relevance of existentialism even spoke of juxtaposing Schell and Sartre on university syllabi.Footnote ²⁷ Lisl Marburg Goodman and Lee Ann Hoff’s exploration of the human condition under the threat of ‘thermonuclear omnicide’ channelled Sartre when they argued, ‘Alienation, then, is a response to overwhelming nuclear anxiety.’Footnote ²⁸ In a similar vein, the novelist Martin Amis wrote that nuclear weapons, which he considered ‘biblical in their anger’ and whose invention was ‘clearly the worst thing that has ever happened to the planet’,Footnote ²⁹ turn us into ‘Einstein’s monsters, not fully human, not for now.’Footnote ³⁰ Attempts to shake humanity out of a complacency on nuclear dangers borne of more than 75 years since their use in war by the United States have regularly returned to the existentialist notion of approaching ‘the challenge of the bomb from every possible angle’Footnote ³¹ in order that ‘the palpable jeopardy of man’s very existence might awaken slumbering human depths.’Footnote ³²

Choice, responsibility, and Sartre’s Nuclear Age

As an engaged public figure, Sartre, like many others wrote publically on the bombing of Hiroshima and Nagasaki in 1945 and the implications for the future of warfare. While far from being his prime political concern, he did comprehend the unprecedented nature of nuclear weaponry early on. In the months following their use against Japan, Sartre observed that ‘the little bomb that can kill a hundred thousand at a stroke and which, tomorrow, will kill two million, brings us up suddenly against our responsibilities.’Footnote ³³ From the outset, like fellow existentialists such as Jaspers, he approached the Nuclear Age through the prism of personal rather than collective responsibility. While, as is discussed further below, Aron (and later others such as Hedley Bull) would conceive of nuclear responsibilities in an explicitly intersubjective sense, the existentialist impulse was to seek peace through individuals taking on their own responsibility for self-criticism and self-education.Footnote ³⁴

In the years that followed, he gave a number of speeches at meetings and seminars held by peace groups and wrote editorials and columns in which he outlined a highly pessimistic, if not fatalistic, view of the likelihood of war (including coining the phrase used in the title of this article). His views on the politics of nuclear weapons soon reflected his progressive political views and philosophical preferences, famously referring to the bomb as a ‘weapon against history’.Footnote ³⁵ He viewed Western nations in particular as wanting a monopoly over the ultimate weapon for purposes of control in the face of progress, writing that, ‘In order to stop the world turning they are threatening to suppress history by liquidating those who make history.’Footnote ³⁶ For Sartre, the bomb was therefore an inherently reactionary weapon, a position that of course would sit awkwardly with its acquisition by revolutionary governments in 1949 (the Soviet Union) and 1964 (the People’s Republic of China).

This led Sartre to be, unlike Aron, an outspoken advocate of nuclear disarmament. At times this was borne of his progressive politics, at other times he joined philosophers and writers such as Bertrand Russell in making the case for nuclear abolition on purely rationalist grounds.Footnote ³⁷ Echoing many of the arguments made by nuclear abolitionists and proponents of the TPNW today albeit in different geopolitical circumstances, Sartre’s writing and speeches on Cold War geopolitics emphasised the oppressive and unjust outcomes felt outside of the two camps of East and West, particularly in the colonised world.Footnote ³⁸ For him, the Cold War nuclear arms race deprived people everywhere of the peace of freedom: ‘Our peace can only have one meaning: it is possible for all nations and all men to muster their own destiny; in a word it is freedom.’Footnote ³⁹ Here we see an alignment of his political response to the Cold War with the emphasis on freedom and choice in his philosophical writings. Other existentialist writers such as Jaspers, and existentialist-adjacent intellectuals such as Hannah Arendt were far less enamoured with the conflation of freedom with peace.Footnote ⁴⁰ Arendt, in particular, was scathing in her appraisal of such a position given the existential risks associated with nuclear use: ‘To sound off with a cheerful “give me liberty or give me death” sort of argument in the face of the unprecedented and inconceivable potential of destruction in nuclear warfare is not even hollow; it is downright ridiculous.’Footnote ⁴¹

Important in the existentialist tradition in general, and central to Sartre’s contribution in particular, are notions of, and debates about, agency. For the IR scholar, agency is about actors and action. For the existentialist, agency is about choice. What the two approaches have in common is a focus on what Colin Wight has identified as ‘the dual notions of meaning and intentionality.’Footnote ⁴² IR scholars have generally conceded the existence of both important structural phenomena and the potential for either individual human or collective (often state) agency as two ever-present factors in world politics whose relative importance for causal explanations can be endlessly debated. The existentialist position by contrast, is a priori critical of structural accounts of human society. Instead it emphasises the agonisingly ever-present conditions of freedom and choice. While structural forces in the form of societal expectations may exist, they do so by virtue of human creation and the choice to conform to, and perpetuate, these constraints. There is no escaping the choice to free oneself of these structures or to choose instead to succumb to them. As Sartre puts it, ‘Choice always remains a choice in a situation.’Footnote ⁴³

Such a relentless prioritisation of agency takes on a particular significance in the Nuclear Age. The ultimate choice for a nuclear-armed decision-maker is whether to make use of this destructive power in a moment of terror produced by the fear that an adversary might strike first. Given the chances, if not likelihood, of any nuclear use leading to retaliation and thereby instigating what strategists refer to (in deceptively neutral language) as a ‘nuclear exchange’, such a decision relates directly to the future of human existence.Footnote ⁴⁴ The stakes could not be higher. This decision is never made under ideal circumstances but instead, under the worst, where time spent deliberating the ‘consequences of our freedom’ and the responsibilities it entails is, by definition, extremely limited. Based on modern ballistic missile flight times, the best estimates for how long a decision-maker would have to decide whether and how to respond to an incoming nuclear attack would be no more than 12 minutes.Footnote ⁴⁵ But for Sartre, no matter how dreadful the decision and no matter the circumstances in which it is made, the freedom to choose is inescapable by virtue of the decision-maker’s human existence. US President Ronald Reagan may have uttered ‘no prayer more fervently than the ancient prayer for peace on Earth’Footnote ⁴⁶ when navigating the threats to human existence posed by the more than sixty thousand nuclear warheads possessed between the United States and Soviet Union in the mid-1980s, but for Sartre, the choices of an individual – whether a nuclear-armed president or otherwise – are theirs and theirs alone:

It is in Sartre’s discussion of freedom and responsibility that some of the distance between he and Aron on questions of peace and war is narrowed. Sartre’s approach to the freedom to choose during war was to emphasise the responsibilities inherent in the human condition. For Sartre, war is not a force external to us for which we must reckon. It is not a structural force that, as Hedley Bull once described it, acts as ‘a basic determinant of the shape the [international] system assumes at any one time’, nor is it ‘a manifestation of disorder in international society.’Footnote ⁴⁸ Instead, the existence of the agent and the war itself are intimately bound together because ‘I am this war which restricts and limits and makes comprehensible the period which preceded it.’Footnote ⁴⁹ Responsibility for the war and our experience of it, for Sartre, lies in what we do and do not choose to do. The first principle of existentialism, as Sartre claimed, is that ‘Man is nothing else but what he makes of himself.’Footnote ⁵⁰ As the famous existentialist phrase goes: existence precedes essence. If there is no God to conceive of human nature, then humans are what they conceive of themselves to be and this is done through the choices they make even, perhaps especially, in war.

The freedom to choose, even under conditions of war, highlights the inescapable responsibilities of human existence and therefore, as we will see in the following section, this brings Sartre and Aron’s thinking on ethical responses to war and violence closer together. Yet it also highlights the limits of Sartre’s reflections on the human condition and war for the Nuclear Age. Following the indiscriminate killing and utter devastation produced by the strategic bombardments of cities such as Dresden, Coventry, and Tokyo in the Second World War, let alone in the aftermath of the atomic bombings of Hiroshima and Nagasaki, Sartre’s writings about freedom, responsibility and war were remarkably unsuited to the new era of aerial bombardment. They would go on to become even less suited to what would soon be dubbed ‘the missile age’.Footnote ⁵¹ In the early 1950s, when Sartre’s popularity was at its height, officials were making public statements about the consequences of a nuclear exchange between the United States and the Soviet Union. In 1956, when asked about the estimated casualties of an American nuclear attack against Russia in which the prevailing winds would spread radiation in a southeasterly direction, General James M. Gavin told the US Senate Armed Services Committee that, ‘Current planning estimates run on the order of several hundred million deaths.’Footnote ⁵² Yet Sartre’s position on the responsibilities arising from an individual’s freedom to choose how to live in any and all situations led him to claim ‘there are no innocent victims’ because ‘we have the war we deserve.’Footnote ⁵³ Still thinking in terms of soldiers on a battlefield in a traditional theatre of war, he argued of the human agent finding themselves at war that, ‘I deserve it first because I could always get out of it by suicide or by desertion; these ultimate [possibilities] are those which must always be present for us when there is a question of envisaging a situation.’Footnote ⁵⁴ This agent-centric understanding of the world simply bears no resemblance to a world in which quite literally a handful of individuals hold the authority to authorise nuclear strikes. Writers such as Elaine Scarry and Daniel Deudney have described this as forms of ‘nuclear monarchy’Footnote ⁵⁵ and even ‘nuclear despotism’Footnote ⁵⁶ in which ‘temporally compressed decisionmaking must be concentrated by necessity into the hands of one individual.’Footnote ⁵⁷ In such a world, the freedom of individuals or even polities to choose under conditions of war is radically different from the pre-nuclear era. The contingency of Sartre’s work in relation to the nature of warfare, and the limits that this produces in terms of his ability to truly reckon with the ethical questions posed by the nuclear revolution, has been captured by a number of critics. As Craig Vassey has identified, when Sartre was attempting to write the final volume in his planned The Roads to Freedom tetralogy in the early 1950s, the Nuclear Age had overtaken him. His characters no longer inhabited the same world that he or his audience did: ‘the world Mathieu inhabits is a prison camp in 1941; the world Sartre now inhabits is the post-Hiroshima world where Korea might well become a nuclear Third World War.’Footnote ⁵⁸

It is not just that having ‘the war we deserve’ leaves individuals living under the nuclear ‘sword of Damocles’ with little room for ‘authentic’ existence without embracing their choice not to escape the dangers of nuclear crises by suicide. It also leaves little guidance for the nuclear-armed decision-maker by way of reckoning with the responsibilities of being able to destroy millions of lives with a single launch order. Once US and Soviet decision-makers had adopted ‘counter-value’ targeting strategies in which civilian population centres are targeted over military sites, decision-makers had to consider the intergenerational effects of possibly killing entire generations of families living in the same city in a single attack. Sartre’s thinking is insightful on the anguish produced by that decision-maker’s consciousness of the consequences of their future decisions alongside their inability to control such decisions at present. His dogged insistence on the fact that our choices define our existence and that those choices are always real can be a remedy for the groupthink and ‘conventional wisdoms’ that lead to complacency about nuclear weapons. This remedy could hardly be more necessary. As one account puts the contemporary approach to the tens of thousands of nuclear warheads sitting in arsenals today:

Such complacency about an everyday existential threat to humanity is both grotesque and profound. Sartre’s exhortation is to resist the strictures of societal expectations and to confront the anguish of being a free agent choosing how to live in the nuclear age – being, as Sartre put it, a ‘little God’.Footnote ⁶⁰

Yet he is more interested in the anguish itself than he is with its real-world consequences and the ethical dilemmas it produces. For example, should the nuclear-armed leader who trusts her own judgement today but does not necessarily trust her successor’s judgement with the same weapons in the future therefore opt to unilaterally disarm? Would it be to act in bad faith to choose not to imagine a future when her own nation might engage in a pre-emptive nuclear attack resulting in the indiscriminate killing of an adversary’s population (not to mention undermining the ‘nuclear taboo’ thereby making further strikes by others more likely)? By perpetuating the status quo of her nation’s privileged position in the global nuclear order rather than engaging in unilateral disarmament, is that leader living an inauthentic life by claiming that she has no choice? Yet by that logic, it would equally be an act of bad faith not to imagine a future in which that adversary may itself choose to pre-emptively strike her own nation having lost the deterrent effect of a retaliatory capability following her choice to unilaterally disarm. This is the dreadful and paralysing state that the leader finds herself in. It would appear that the tragic nature of an anarchic international system has deprived her of any real choice. Yet Sartre tells us that choice is inescapable, that the ‘first act of bad faith is to flee what it can not flee, to flee what it is.’Footnote ⁶¹ The ethical implication is clear: we must actively deliberate on these questions and explore alternative options. But on the criteria that might guide such deliberation, Sartre is far less clear.

Living with nuclear weapons means that a handful of individuals at any one time quite literally have the freedom to make choices that affect the fate of the rest of humanity. They do this every day. And while the ‘bad faith’ acceptance of this may result in the perpetuation of an unnecessary threat to human existence, we should not assume that it is only consciousness and being that will break us out of such madness. At times when leaders have been forced into an understanding of their freedom of action and the severe anguish it induces, their responsibilities have not been lost on them. The then US Attorney General Robert Kennedy wrote of his brother’s fateful decision-making during the thirteen days of the Cuban Missile Crisis of 1962:

Rather than hiding behind the enormity of the situation, the sheer destructiveness of the arsenals of both sides, or some reading of the inevitability of conflict due to the essence of human nature, if his brother’s account is correct, John Kennedy was instead reckoning with his freedom to choose in the Nuclear Age with the upmost dedication and authenticity. Yet Kennedy came dangerously close to ordering a military strike, which would very likely have resulted in a massive nuclear exchange between the Soviet Union and the United States. Such authenticity is no barrier to a nuclear-armed decision-maker choosing to ‘protect’ their own population by using nuclear weapons. Nor did the recognition of his own freedom to choose nuclear annihilation lead Kennedy, nor his successors, towards Sartre’s own preference for nuclear disarmament. It took another five years before the US nuclear stockpile would peak at over 31,255 warheads and until 1986 for the Soviet Stockpile to hit its peak of over 40,159 warheads.Footnote ⁶³ Despite the Cuban Missile Crisis resulting in a much greater awareness of the dangers of nuclear crises among both practitioners and the general public, it was far from the last nuclear ‘close call’ of the Cold War.Footnote ⁶⁴

Nor should we assume that individuals accepting their responsibility to seriously grapple with the ethical decisions that they delegate to elites (political decision-makers and defence officials), rather than hiding behind the inauthentic denial of their own freedom to choose, would necessarily lower the risks of nuclear holocaust. Recent research into public opinion and willingness to sanction the use of nuclear weapons, even when civilian populations would be targeted, shows that significant proportions of the public in a number of nuclear-armed states are not dissuaded by norms against nuclear use and the deliberate targeting of civilians.Footnote ⁶⁵ The freedom to choose can also entail the choice of nuclear strikes. Without going beyond the need to ask questions about how we have come to live so easily with nuclear weapons, Sartre’s existentialism only offers limited pathways for surviving the existential threats of the Nuclear Age.

Structure, international society, and Aron’s conception of nuclear responsibility

Unlike his (one-time) friend and interlocutor Sartre, Raymond Aron devoted much of his thinking and writing to the specific ethical and strategic choices faced by states and individuals living with the bomb. Along with others such as Bernard Brodie, John Herz, Thomas Schelling, Albert Wohlstetter, Herman Kahn, and Hedley Bull, Aron is widely considered one of the key thinkers of early Cold War nuclear scholarship.Footnote ⁶⁶ In large part, his early, but also sustained, focus on nuclear weapons was a product of his wartime experience and how quickly he comprehended the radical nature of the nuclear revolution. In his memoirs, Aron would recount that ‘the epistemological questions that had excited me before 1939 barely interested me in 1945.’Footnote ⁶⁷

However, more than simply an IR or strategic studies figure, Aron also wrote widely on history, philosophy, and sociology. All three of these areas informed his outlook on the world in general and on nuclear weapons in particular. He rejected a teleological view of history in all forms – including Marxism, which would lead to a good deal of his differences with Sartre. His general pessimism about the nature of world politics has often led him to be associated with the realist tradition. Rather than joining Sartre in calling for the ambitious goal of nuclear abolition, he was an early advocate of settling for the more modest goal of deterrent rather than warfighting postures. He also advocated policies that might create the degree of stability found in mutual vulnerability – what would become known as the concept of mutual assured destruction (MAD).

While often not discussed as such, the doctrine of MAD relies on an intersubjective understanding between two or more parties about deterrence in general, and the requirements of a deterrence-centred nuclear posture in particular. Without at least a minimum level of agreement as to what constitutes vulnerability in the Nuclear Age, and what kinds of deployments and postures either increase or decrease that vulnerability, there can be no stability based on the ability to destroy the other being mutual. If one side interprets the other’s moves as signalling a confidence in their own invulnerability, they are likely to fear that an attack is imminent. Thomas Schelling, while operating in the rationalist mode of bargaining theory, referred to this as ‘the dialogue of competitive armament’ – a process of intersubjectively arriving at common ideas and practices that reduced the risk of war via what he thought of as ‘feedback in the arms competition’.Footnote ⁶⁸ Echoing Aron’s appreciation for the relational nature of arriving at a nuclear order based on deterrence rather than warfighting, Schelling wrote that it is not enough for one side to adopt a posture of restraint but that ‘the other side must know it, must be equipped to perceive restraint if it occurs, and must have equipped itself to be discriminating in its own fashion, too.’Footnote ⁶⁹ MAD was not some kind of automatic condition that naturally followed from the realisation of the immense destructiveness of first atomic, and later thermonuclear, weapons. It was a way of surviving in this new age that could only be reached through common, even if tacit and even reluctant, understanding between the superpowers in their unique historical and social setting.Footnote ⁷⁰ Therefore, developing norms of nuclear restraint became integral to surviving the tensions and crises that had already become hallmarks of this new era of threatened mass destruction. The development of norms was grist to the mill for the sociologically minded Aron.

Instead of focusing on freedom and choice like his former schoolmate, Aron approached the question of responsibility in the Nuclear Age through the lens of societal norms. Today we might think of this as being a broadly constructivist, or perhaps even more accurately, English School approach to IR. Just as Bull wrote about the social institution of the ‘managerial’ role of the great powers – what he and others termed the ‘great responsibles’ – Aron envisaged social norms as being the greatest restraint on the nuclear-armed superpowers.Footnote ⁷¹ For Aron, ‘Inter-state relations consist of social behaviour … Diplomatic-strategic behaviour … reckons on the reaction of the very person in relation to which it orients itself … .’Footnote ⁷² In some ways this is reminiscent of the work of existentialist writers, particularly Sartre and Beauvoir, who focused on the relational nature of self and other in defining existence. Yet Aron’s pessimism is never far from his analysis and it is the relational element that drives the need for societal norms to dampen Cold War rivalry, ‘The authority exercised by each of the major powers on its bloc is directly related to the fear aroused by the other.’Footnote ⁷³ But importantly, the social nature of the international system – or what should therefore be rightly termed international society – is also evident in the recourse by practitioners to claims of legitimacy. Diplomatic behaviour also ‘always attempts to justify itself, thereby admitting the authority of values or rules.’Footnote ⁷⁴ Contemporary calls for a return to notions of ‘nuclear responsibility’, not least in the context of Russia’s invasion of Ukraine, draw directly on this line of argument originally developed by Aron and others.Footnote ⁷⁵

In Aron’s view, not only had the invention of nuclear weapons forced humanity to consider the future of its own existence like never before, it had altered the social fabric of interstate relations. As he put it, ‘What are called weapons of mass destruction have changed something in the course of relations between what are called sovereign states. They have changed neither the nature of men nor that of political units.’Footnote ⁷⁶ His approach to trying to understand the impact of nuclear weapons was a specifically ‘third image’ one.Footnote ⁷⁷

In particular, it was a social understanding of structural change in world politics. This sits in direct contrast with Sartre’s agent-centred approach in which the only way to exist authentically in the Nuclear Age is to continue to insist on the individual’s freedom to choose their own path, regardless of societal norms. Most importantly, since 1945 this has meant choosing to reject – and even resist – the frameworks and norms that have led us to living with the threat of omnicide as a normal condition in world politics to be ‘managed’ like other challenges.

For Aron, the first change that nuclear weapons had made to the social fabric of interstate relations was to convince the possessors of the ultimate weapon that this power must be deployed towards defensive, rather than offensive, purposes. This would mean that, rather than seeking gains in warfighting from nuclear weapons, both sides of the intense superpower rivalry would instead posture their forces to deter attack from the other side only. Aron, a keen student of the history of warfare, identified the revolutionary nature of this shift in thinking about the weapons of war. While others, like both Sartre and Jaspers looked to a fundamental change in consciousness in order meet the challenges of what they thought of as a completely new world, Aron thought of the nuclear revolution as a change in the nature of warfare, but not in the basic drivers of international conflict.Footnote ⁷⁸ Therefore, it made sense to look to familiar ways of restraining relations between powerful states, such as the balance of power, diplomacy, and even international law, and consider how these practices and ideas might be adapted for a new age.

Rather than ‘suppressing history’ as Sartre put it, for Aron, the radical departure posed by nuclear weapons from the weapons of the past amounted to ‘the acceleration of history’.Footnote ⁷⁹ The effect was to severely limit the freedom of action of the superpowers for the sake of ensuring their own, and humankind’s, continued existence. This new way of thinking about military technology and the effect of the agreed upon understanding on it by both sides of the Cold War divide – in spite of its regular testing and challenging in nuclear crises and ‘near misses’ that Aron was very much aware of – might almost lead to what he termed an ‘optimistic theory of peace by fear’. In 1962 – the year of the Cuban Missile Crisis – he wrote

In contrast to Sartre, Aron emphasised the pacifying effects of social structure – mutual restraint due to the sheer destructiveness of these weapons and a shared understanding that deterrence was the best path to stability – over the choices and freedoms of agents. This was not the material structure of the nuclear balance favoured in the analysis of his fellow travelling realist strategists. Instead, for Aron the destructive force of the bomb had led to a revolution in thinking. It was not the material threat itself but how the decision-makers chose to respond that resulted in the absence of nuclear war: ‘when some states possess means of destruction against which all the others cannot protect themselves, and which they cannot respond to either, the essential focus lies predominantly in the minds of the group of men responsible for the diplomacy or strategy of the nuclear powers.’Footnote ⁸¹ So while agency mattered to Aron too, for him it was the intersubjective agreement on legitimate nuclear practices built between agents over time – the creation of a social structure – that would reduce the threat of nuclear war.

In addition to the self-restraint borne of a mutually agreed upon (however rationally-based) approach to deterrence and mutual vulnerability, Aron also pointed to a wider societal norm that constrained the nuclear-armed actors – not just the superpowers. As early as 1958, he was articulating a notion of a norm against nuclear use – that which would become known in time as the ‘nuclear taboo’.Footnote ⁸² He characterised this as a situation where nuclear weapons, ‘like gold reserves used to back currency’, were ‘buried in the ground, and accumulated in stockpiles’.Footnote ⁸³ This led to the positive outcome in his view that nuclear-armed decision-makers were ‘paralysed’ by a taboo against actually using these weapons. The taboo and the agreed upon understandings of the workings of MAD were two sides of the same coin, both lowering the chances of nuclear Armageddon. Aron wrote that ‘it does not seem to me either intellectually right or politically opportune to assert that nothing could stop a total war the moment the atomic taboo was violated.’Footnote ⁸⁴ In other words, the taboo bolstered deterrence, but the latter could be restored even in the event of a so-called ‘limited’ nuclear war.Footnote ⁸⁵

As a key figure in French sociology circles – even if adopting the position that Peter Baehr has described as an ‘honoured outsider’Footnote ⁸⁶ – it is not surprising that Aron’s position on human freedom and societal regulation echoes that of one of the sociologists he most admired, Emile Durkheim. When describing Durkheim’s work, Aron could almost have been describing himself: ‘In a certain sense, Durkheim’s thought is conservative; it seeks to restore social consensus and thus reinforce the authority of collective imperatives and prohibitions.’Footnote ⁸⁷ Whereas existentialism rejects societal authority in favour of an ethic of personal responsibility (to live authentically is to recognise the freedom to defy social norms), Aron embraced Durkheim’s small ‘c’ conservatism. But in Durkheim, Aron also recognised a liberalism that was evident in his own work, ‘A sociology justifying rationalist individualism but also preaching respect for collective norms – such, it seems to me, is Durkheim’s ideal.’Footnote ⁸⁸ Durkheim was not simply interested in the societal regulation of human freedom but instead in the interaction between the conscience collective and individual emancipation. As one account puts it, ‘the very prerequisite for this emancipation is the transfiguration in human existence produced by society. Thus there is no inherent opposition between “regulation” and “freedom”: the first is the condition of the second.’Footnote ⁸⁹

Aron’s pessimism does not necessarily require an outright rejection of existentialism. Instead it rests upon an assumption that the temptation to slide back into what the existentialist would think of as an ‘inauthentic’ life is ever present. This is not a theoretical proposition but an empirical observation. As Sartre’s fellow existentialist interlocutor Maurice Merleau-Ponty put it, ‘It would seem that the communion between a man and his power to choose cannot long be endured’ before many succumb to ‘the rule of a fairly conservative reason’ whether this be the strictures of political ideology, the escape of religious faith and doctrine, or the socialising pressures of norms.Footnote ⁹⁰ For Aron, therefore, when it comes to living with weapons that threaten humanity’s very existence, those norms can either make nuclear use more or less permissible and therefore more or less likely. His pessimism leads him to opting for those rules and norms that, at the very least, lower the risk of a nuclear exchange – even at the expense of Sartre’s preferred goal of nuclear abolition.Footnote ⁹¹

Whereas Sartre worried about humans being so ‘immersed in the historical situation’ that they fail to ‘even imagine that things can be otherwise’,Footnote ⁹² Aron saw that some humans were quite capable of imagining alternative futures where the norms of international society at that moment in history did not inhibit the actions of nuclear-armed states. That is what concerned him most. He put it rather pointedly, ‘Heaven forbid that a statesman might exist who would dream that nuclear weapons could not only be deterrent weapons – that is instruments to be used in human dialogue – but also arms of extermination.’Footnote ⁹³ It is perfectly possible for individuals to reject international norms, like the nuclear taboo, and opt to instead use the weapons at their disposal.

It was to norms such as the nuclear taboo and agreed upon understandings about MAD and responsible nuclear great power management that seemed to him to offer a path to continued human existence. Rather than championing the freedom to choose how to live one’s life as the only path to authenticity, Aron championed the regulative effects of societal norms instead. This led him to what he described as ‘the true question concerning the future’ in relation to his dual-track reading of norms of deterrence and the nuclear taboo as the pillars of a fragile social order at the international level:

The fragility of the global nuclear order that Aron wrote of decades ago persists and, if anything, international society may be approaching an even more precarious moment in history. Nuclear threats have returned to the lexicon of world politics with a regularity not seen since the height of the Cold War.Footnote ⁹⁵ New technologies are being developed and deployed – often outside of the traditional realm of nuclear weapons and their delivery systems – that challenge old ways of thinking about MAD and the nuclear revolution.Footnote ⁹⁶ For the first time since their invention, the challenge of avoiding nuclear war will be set against a multipolar distribution of power. Even otherwise robust and widely adhered to norms of non-proliferation may now be under challenge.Footnote ⁹⁷ It would appear that the challenges faced by Sartre, Aron, and their contemporaries have not so much faded as morphed into new dilemmas of an existential nature.

Conclusion: The rights and wrongs of Sartre and Aron in the Nuclear Age

It was once common to hear French intellectuals remark that they would prefer to be ‘wrong with Sartre than right with Aron’. What the discussion above may point us towards is a slightly different version of this. It would seem that Sartre encourages us to ask the right questions, while Aron gives us some answers that might actually reduce the likelihood of nuclear war.

Sartre reminds us of what ought to be the daily anguish of choosing to live in a nuclear-armed world and reminds us that the decision to do so is real. A state that is not disarming its arsenal is not just existing within the bounds of an anarchical international system and, accordingly, being deprived of choice. More than this, even the international norms that Aron pointed to in producing some degree of global order, still tolerate the daily possibility of thermonuclear omnicide. ‘International society’, the ‘global liberal order’, or the much-discussed ‘international rules-based order’ all allow for a small minority of states to hold the fate of the rest of humanity in their hands due to their possession of the world’s most destructive weapon. There is nothing natural or inescapable about this condition. Sartre’s position forces us to ask difficult questions about nuclear futures and mitigates the sense of familiarity that has crept into the way we live with the ability to destroy ourselves at a moment’s notice every day. As Robert Jervis put it, ‘The idea that not only could we die at any moment – this has been true for any given individual throughout history – but that everyone and everything we care about could be destroyed in a twinkling, must remain always frightening, however familiar it is.’Footnote ⁹⁸ Just as freedom is fundamental to existence for Sartre and is therefore inescapable, so too is the ethical minefield of living with nuclear weapons inescapable for Jervis: ‘None of us can, nor should we, put the nightmare of nuclear holocaust out of our minds.’Footnote ⁹⁹

More than simply questioning the conventional wisdoms that guard the global nuclear order, Sartre pushes us to remember that structures of insecurity and fear are created by agents and can be undone, even transcended by agents too. He reminds us, as Hugh McDonnell puts it, of ‘the mutual unfreedom linking oppressor and oppressed, but also that subjugation was never a closed situation and could be transcended.’Footnote ¹⁰⁰ Decisions about how to reduce – even eliminate – the existential threat posed by nuclear arsenals, made up of tens of thousands of warheads even today, are within our grasp and to argue otherwise is to completely misunderstand the role of nuclear weapons in world politics.

Yet Sartre’s existentialism also gives us little basis for making decisions about how to survive a world of persistent nuclear dangers today – even in terms of judging the relative merits of one or other paths to a world without nuclear weapons. Other existentialist (or existentialist-adjacent) thinkers like Jaspers may have more to offer, albeit in ways that depart from pure existentialism and are therefore more Aron than Sartre-like. Jaspers foresaw the need to reflect on the concrete ethical and political questions that the existential threat posed by atomic power posed, writing in 1958 that ‘Either all mankind will physically perish or there will be a change in the moral-political condition of man.’Footnote ¹⁰¹ In a similar vein, Camus’ remarkably solidarist English School-like response in 1945 to the news of the bombing of Hiroshima was to broaden this out to thinking about the rights and responsibilities of states in international society: ‘… we refuse to see anything in such grave news other than the need to argue more energetically in favour of a true international society, in which the great powers will not have superior rights over small and middle-sized nations …’.Footnote ¹⁰²

Perhaps worse than Sartre’s silence on the ethical criteria that we might use to evaluate decisions about, for example, nuclear use, he also leads us towards a wholesale rejection of societal norms aimed at maintaining the status quo. The status quo for Sartre can only ever be the problem. Sartre’s position pits agency against structure rather than Aron’s more conservative approach, which sees agents as purposely, rather than unthinkingly, creating those structures. For Aron, the societal norms that underpin both MAD and the nuclear taboo are what have kept states from annihilating each other in an all-out nuclear exchange and these norms should therefore not be cast aside lightly. Given the decline of formal strategic arms control over the last twenty years, in which mutual and regular accusations of non-compliance and a new norm of unilateral treaty withdrawal has almost entirely replaced the negotiation of new agreements, it is hard to escape Aron’s emphasis on the precariousness of social norms that limit nuclear dangers.Footnote ¹⁰³

If we are to be right with both Sartre and Aron and survive the Nuclear Age long enough to see its end, then bridging the distance between Sartre’s questions and Aron’s answers seems to be the deeply problematic but agonisingly unavoidable way forward. Reminding complacent publics and decision-makers of the moral disgrace that is the continued existence of tens of thousands of inherently indiscriminate and staggeringly destructive weapons must be central to galvanising political will for navigating what is already looking to be a more dangerous era. But the task is more complex than a simple awakening of humanity to its freedom to choose alternative nuclear futures. The shock of Russia placing its nuclear forces on what President Putin described as ‘higher combat alert’ in early 2022 during its invasion of Ukraine was a crucial reminder that not all alternative nuclear futures are safer than today’s nuclear present.Footnote ¹⁰⁴ Building the common ground necessary between states to ensure that social understandings about appropriate behaviour in such a dangerous era is not undermined along the path to a disarmed world will be equally as important and as difficult. Sartre’s questions and Aron’s answers are likely to remain our best hope for some time.