Abstract
This article grapples with the justifiability of nuclear deterrence in the aftermath of Russia's war of aggression against Ukraine. Disillusioned about the failed promise of nuclear disarmament, as well as other ethical issues inherent to nuclear weapons, Pope Francis has attached the immorality label not just to the use of the Bomb but also to its very possession. This step, which his predecessors hesitated to take during the Cold War and the quarter of a century after the fall of the Berlin Wall, has received considerable attention. However, these assessments precede the war against Ukraine. Given that the regime of Vladimir Putin has repeatedly made nuclear threats in the context of this war, and a Cold War 2.0 of sorts has returned, there is reason to reappraise Francis's argument on nuclear weapons for a post-2022 era. I argue with regret that in light of the contemporary security environment it would be a sign of irresponsible statecraft to abandon the nuclear deterrent unilaterally. At the same time, I hold that a renewed and genuine effort needs to be made not just to avoid nuclear war but to create a culture that one day will lead to complete nuclear disarmament.
Introduction
Catholic thinking on war and peace has been receiving much critical attention lately in the context of the ongoing war against Ukraine. Pope Francis, in particular, has been criticised for not being more outspoken against Russia's unjust war of aggression. 1 Besides the Holy See's traditional aspiration to be seen as a trustworthy mediator capable of facilitating peace deals, clearly, Francis rejects using the language of just war. 2 At the same time, however, the pope does not take a pacifist position, as he has affirmed both Ukraine's right to self-defence and the right of third party states to supply weapons to Kyiv. 3 Although he renounces the language of just war, Francis has effectively followed the established Church teaching on the ethics of war in all but name. His position is representative of the contemporary Catholic position commonly characterised as a ‘presumption against war’. 4 This position is enshrined in the Catechism of the Catholic Church that spells out the conditions for what it calls ‘legitimate defense by military force’. 5
While it would thus be wrong to portray Francis as moving the Church's teaching on war and peace into a radically new direction, there is one specific area in which the pope has in fact changed the established position, namely, the ethics of nuclear weapons. Francis has broken with the previous Catholic position, which rejected use but allowed conditional possession of nuclear weapons, and the Holy See was among the first parties that signed and ratified the TPNW, the Treaty on the Prohibition of Nuclear Weapons. 6 Disillusioned about the failed promise of nuclear disarmament, as well as other ethical issues inherent to nuclear weapons, Francis decided to attach the immorality label not just to the use of the Bomb but also to its very possession. This step, which his predecessors hesitated to take during the Cold War and the quarter of a century after the fall of the Berlin Wall, has received considerable attention. However, these assessments precede the war against Ukraine. 7 Given that the regime of Vladimir Putin has repeatedly made nuclear threats in the context of this war, and a Cold War 2.0 of sorts has returned, there is reason to reappraise Francis's argument on nuclear weapons for a post-2022 era. To do that, I begin this article by tracing the development of Catholic nuclear ethics from reluctantly accepting possession during the Cold War to condemning both use and possession of nuclear weapons in 2017. Next, I reappraise the new position in the light of Russia's war against Ukraine. I argue with regret that in light of the contemporary security environment it would be a sign of irresponsible statecraft to abandon the nuclear deterrent unilaterally. At the same time, I hold that a renewed and genuine effort needs to be made not just to avoid nuclear war but to create a culture that one day will lead to complete nuclear disarmament.
The Catholic Take on Nuclear Deterrence: From Reluctant Acceptance to Condemnation
It seems fair to argue that the Catholic position on nuclear weapons up until Pope Francis constituted a compromise of sorts that was formed during the Cold War and survived until the current pope's clear break with it. Since Hiroshima and Nagasaki, it was readily apparent that the use of nuclear weapons would inevitably violate the jus in bello code of just war. Consequently, the popes concluded that their use would be immoral and their very existence constituted a grave threat to humanity. As a result of this, they identified a moral obligation to abolish nuclear weapons. At the same time, however, the popes also appreciated the difficulty of this task as well as the deterrent effect of nuclear weapons, which, they reasoned, might play a fundamental role in preventing a third World War. Consider, for example, Pope John XXIII, who in his 1963 encyclical Pacem in Terris, left no doubts about his general attitude toward the Bomb: ‘Nuclear weapons must be banned.’
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However, John XXIII also acknowledged that the immense destructiveness of nuclear weapons comes with a deterrent effect: While it is difficult to believe that anyone would dare to assume responsibility for initiating the appalling slaughter and destruction that war would bring in its wake, there is no denying that the conflagration could be started by some chance and unforeseen circumstance. Moreover, even though the monstrous power of modern weapons does indeed act as a deterrent, there is reason to fear that the very testing of nuclear devices for war purposes can, if continued, lead to serious danger for various forms of life on earth.
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Two decades later, in 1982, Pope John Paul II provided a succinct summary of the Catholic position on nuclear weapons that Francis would inherit another three decades later: ‘In current conditions “deterrence” based on balance, certainly not as an end in itself but as a step on the way toward a progressive disarmament, may still be judged morally acceptable. Nonetheless in order to ensure peace, it is indispensable not to be satisfied with this minimum which is always susceptible to the real danger of explosion.’ 10
In a nutshell, underpinning the popes’ argument on possession of nuclear weapons was a distinction between two forms of peace, respectively referred to as ‘peace of a sort’ and ‘genuine peace’. 11 The former type, characterised by the mere absence of war, falls short of the promise of a ‘genuine peace’ that overcomes indirect and structural violence. However, although being non-ideal, a ‘peace of a sort’ was seen as the only realistic option during the Cold War, and could be achieved by the deterrent effect of nuclear weapons. While accepting possession for the sake of a ‘peace of a sort’, however, the popes made sure to attach conditions to it. In particular, they tied their acceptance of possession, in line with John XXIII's early call for a ban, to a credible effort to disarm. Ideally, there would be no nuclear weapons, but, as they existed, their possession would be morally acceptable as part of an interim ethic aimed at keeping a ‘peace of a sort’, as long as there was a commitment to rid the world of this most destructive of weapons. 12 Even in the light of reluctantly affirming nuclear deterrence, however, for the Church that rationale, as Lisa Sowle Cahill points out, ‘has never been justifiable in reasoned ethical terms’. 13
Having noted the Cold War context of the Catholic interim ethic, when Francis was elected pope in 2013 the international security environment had changed markedly. 14 Although the Iron Curtain had come down more than two decades earlier, the threat posed by nuclear weapons had not gone away. Instead of having moved toward Global Zero, the international community was dealing with the spread of nuclear technology. In addition, the ostensible certainties of a bipolar world during the Cold War had made way for a seemingly more unstable multipolar one. Moreover, in Francis's eyes, the continuing arms race was a morally problematic aspect of international affairs that harmed ‘the real priorities facing our human family, such as the fight against poverty, the promotion of peace, the undertaking of educational, ecological and healthcare projects, and the development of human rights’. 15 As a result of these factors, Francis decided to break with the interim position on nuclear weapons, declaring that ‘the threat of their use, as well as their very possession, is to be firmly condemned’. 16 Arguably deciding to turn away from the ‘peace of a sort’ concept and embracing the idea of a ‘genuine peace’, Francis stated: ‘International relations cannot be held captive to military force, mutual intimidation, and the parading of stockpiles of arms. Weapons of mass destruction, particularly nuclear weapons, create nothing but a false sense of security. They cannot constitute the basis for peaceful coexistence between members of the human family, which must rather be inspired by an ethics of solidarity.’ 17 The pope followed up on the new position two years later when he visited the Peace Memorial in Hiroshima and employed the term ‘immoral’ with regard to the possession of nuclear weapons: ‘With deep conviction I wish once more to declare that the use of atomic energy for purposes of war is today, more than ever, a crime not only against the dignity of human beings but against any possible future for our common home. The use of atomic energy for purposes of war is immoral, just as the possessing of nuclear weapons is immoral, as I already said two years ago.’ 18 Surrounded by survivors of the Hiroshima bombing, Francis clearly rejected deterrence thinking: ‘How can we propose peace if we constantly invoke the threat of nuclear war as a legitimate recourse for the resolution of conflicts? May the abyss of pain endured here remind us of boundaries that must never be crossed.’ 19 Importantly, the pope's powerful rhetoric was translated into statecraft when the Holy See signed and ratified the TPNW in 2017.
One Word, Many Interpretations: On the Complexity of the ‘Immorality’ of Possession Argument
While Francis's condemnation of both use and possession of nuclear weapons as ‘immoral’ could not be clearer in its wording, the question of how to interpret it continues to be debated. There are scholars who see Francis's argument as designating possession as an intrinsic moral evil, whereas others see the immorality claim more as a prudential judgment that is grounded in an assessment of the post-Cold War international security environment. 20 In addition, there are voices who argue that in the light of the immorality claim, practising Catholic soldiers now need to resign from nuclear-related positions, whereas others, including myself, argue that Francis's position does not necessarily have to be interpreted in such a way. 21 It is also important to note that the group of scholars that are grappling with these questions come from different fields, including ordained members of the Catholic hierarchy, theologians, and philosophers. Bringing in my own background as an International Relations scholar, my main concern in this article is the nature of the international system that arguably played a crucial role in the run up to the decision to reject nuclear deterrence as ‘immoral’. While taking note of the theological and philosophical arguments that have featured in the discussion about Francis's take on the atom bomb, and noting that theology and philosophy have generally been major influences in the development of just war thinking, I seek to employ just war as a tradition of statecraft that is in the service of the common good. I am thus embracing the classical conceptualisation of Thomas Aquinas who argued that armed force could only be authorised by those responsible for the common good of the political community, if they did so for a just cause, and with right intention. 22 In other words, the common good and its protection from outside security threats takes pride of place. Importantly, concentrating on the primacy of the common good can tell us something about nuclear ethics. Francis's heartfelt condemnation of both use and possession as ‘immoral’ should be seen as a praiseworthy new approach to the long-held papal desire to rid the world of this most destructive of weapons. At the same time, however, a just war framework that seeks to inform responsible statecraft cautions against abandoning nuclear weapons unilaterally, and doing so during what has been called a Zeitenwende, the dawn of a new era, ushered in by the war against Ukraine. 23 Giving up on the nuclear deterrent now would be a profound threat to the security of the peoples an aggressive Russia might chose to threaten, or even attack, next. It would be an irresponsible act of statecraft.
In consequence, state leaders are facing a dual task. On the one hand, just war as statecraft asks those in authority to try the ‘art of the possible’ in achieving a Global Nuclear Zero and to manage carefully the profound risks that are inherent to nuclear weapons. On the other, it requires that they closely observe and react to the ‘signs of the time’. 24 Responding to the ‘signs of the time’ has of course been a prominent theme in Catholicism since Vatican II (1962–1965), seeking to listen to and learn from the circumstances of the day. In the context of this article, it deserves to be mentioned that in Pacem in Terris John XXIII used ‘Signs of the Time’ as the heading for the section that expressed the idea that war was becoming increasingly less justifiable: ‘Men nowadays are becoming more and more convinced that any disputes which may arise between nations must be resolved by negotiation and agreement, and not by recourse to arms.’ 25 This very challenging dual task is captured succinctly by Cahill when she argues that possessing and threatening the use of nuclear weapons as part of a deterrence strategy are ‘morally fraught courses of action that properly result in uneasy consciences’. 26 In her eyes, nuclear deterrence constitutes ‘a moral conundrum because it is both theoretically unjustified and practically necessary as a condition for negotiating arms reduction and nuclear abolition’. 27 Grappling with this ‘moral conundrum’ in the context of the war against Ukraine, in the next section I will make an attempt at suggesting an approach that does justice to both ends of the dual task that state leaders are facing. Indeed, I do so with an ‘uneasy conscience’, as it lets me argue in favour of a continued role of nuclear deterrence as part of a revived effort to achieve a Global Nuclear Zero. In so doing, I provide a response to the immorality claim that acknowledges that my response to the ‘signs of the time’ is one possible response, but not the only one. There can be more than one justifiable response if we follow what the late Drew Christiansen referred to as Francis's ‘morality for adults’, 28 a morality that puts a premium on the individual discernment of the ‘signs of the time’.
Nuclear Weapons after Ukraine: Grappling with the Immorality of Possession Argument
Having provided an account of the Catholic perspective on nuclear weapons and how it has evolved, I now return to the war against Ukraine with which I began this article. I am of the view that, not unlike the increased interest in just war thinking the conflict has sparked generally, the Russian war of aggression has once more highlighted the enduring relevance of grappling with nuclear ethics. After all, the fear of a nuclear escalation of the war has been a major concern for both Ukraine and NATO leaders, a concern that the Russian regime has repeatedly tried to exploit by threatening the use of nuclear weapons. Upon reflection, while I embrace the position cited above that ‘nuclear deterrence has never been justifiable in reasoned ethical terms’, alas there is no realistic prospect of achieving a ‘genuine peace’ in the near or even intermediate future. In fact, beyond the ongoing Russian aggression, the continuing tensions with an increasingly assertive China call for a prudent maintenance of a ‘peace of a sort’, which will include a continued nuclear deterrence posture. In that sense, my take is a nod to what Augustine of Hippo referred to as tranquillitas ordinis, the peace of order that can be achieved in this world, but that is distinct from the heavenly shalom. 29 As George Weigel notes, ‘As an eschatological reality, shalom stands in judgment on the achievements of peace as political community in this world, reminding us that the task of stewarding the creation is never finished. Peace as dynamic, rightly ordered political community is an interim ethic: it offers a goal that can be realistically pursued in this world.’ 30 It goes without saying that the parallel between the pairs of peace of a sort/genuine peace and tranquillitas ordinis/shalom has obvious limitations, but I do think that Augustine's conception of tranquillitas ordinis, in both what it can and cannot achieve, can teach us something about nuclear ethics. Following this argument, even if we accept a continued role of nuclear deterrence for the time being, we must never be content with that state of affairs and there is an obligation to constantly remind ourselves of the dangers that are inherent to nuclear weapons. As the international security scholar Scott Sagan puts it succinctly, ‘Relying on nuclear deterrence … is like walking across thin ice. The fact that we have done it for so long without falling through does not mean that we should assume that the ice will hold forever.’ 31
I appreciate that affirming a continued role of nuclear deterrence will be deeply unsatisfying for many. Personally, it pains me to make this argument. In addition, I accept that critics may read my argument as simply calling for a return to the previous Catholic interim ethic on nuclear weapons. My response to these critics will be that the ‘immorality’ of possession asks state leaders, and in fact all of humankind, to genuinely do more than before to free the world of the constant threat posed by nuclear weapons. Above all, this will require a changed mindset regarding the atom bomb. I am not seeking to suggest that such a change can happen quickly; the notorious libido dominandi certainly forms a perennial obstacle to a genuine peace that would enable states to let down their nuclear guards. However, Francis's ‘immorality’ argument on possession provides a timely impetus to step up the game of nuclear disarmament. How can this be done? There certainly is no single answer, but the Catholic tradition provides important pathways that should be explored. In the following concluding section, I will propose an approach to nuclear deterrence that grapples with both elements of the dual task the just war tradition hands to state leaders regarding nuclear weapons, and that responds to the ‘signs of the time’.
Responding to the ‘Dual Task’: A Practical Approach
Following from my desire to find a morally justifiable solution that considers both aspects of the dual task identified above, I propose to further accentuate the conditions attached to the reluctant toleration of the possession of nuclear weapons on the way to abolition, and to make a comprehensive effort to change the mindset that makes such possession necessary. It is on the latter aspect, I will argue, that the Catholic debate can provide particularly important insights.
The first response to the dual task state leaders need to tackle is to bolster the conditions attached to nuclear deterrence in the contemporary international security environment. In making this argument, I draw on the insights of a recent symposium published in the journal Ethics & International Affairs that reappraised a seminal book authored by the political scientist Joseph Nye entitled Nuclear Ethics. 32 In this book, first published in 1986, Nye proposed ten criteria that could help to avoid nuclear war and that were based on a conditional acceptance of nuclear deterrence: (1) Maintain a credible nuclear deterrent; (2) Improve conventional deterrence; (3) Enhance crisis stability; (4) Reduce the impact of inevitable accidents; (5) Develop procedures for war termination; (6) Prevent and manage crises; (7) Invigorate nonproliferation; (8) Limit misperceptions through improved communication; (9) Pursue arms control negotiations; (10) Reduce reliance on nuclear weapons over time. It almost goes without saying that many of these concerns have featured prominently in contributions made by major voices within the Church, including the seminal 1983 pastoral The Challenge of Peace put forward by the US Catholic bishops. 33
In his contribution to the 2023 symposium, Nye argued for the enduring relevance of these criteria, thirty-seven years after the first publication of his book. 34 According to Nye, although we have arguably entered into a ‘new nuclear age’ that is characterised by renewed nuclear threats as well as technological change through the internet, artificial intelligence and cyberattacks, his ten criteria to avoid nuclear war remain relevant. Almost as if replying directly to Francis's immorality argument, Nye agrees that abolition is a laudable long-term objective, ‘but it does not seem credible or possible in the near term of world politics. … The greatest evil is not the existence but the use of nuclear weapons, and reducing that probability should be our moral and policy focus.’ 35 Interestingly, Nye's argument that the existence of nuclear weapons is not the greatest evil suggests that in his eyes possession does in fact constitute an evil, if one of a lesser magnitude. There is thus a direct connection between his argument and the Catholic debate that has sought to apply the distinction between intrinsically wrongful acts and acts of lesser moral wrongfulness to the use versus possession distinction.
Arguably, the distinction between two types of moral wrongfulness can lead the way toward an understanding of nuclear deterrence that is fit for the challenges that confront humankind today. Ideally, we would live in a world without nuclear weapons and we should see it as a moral obligation to move toward abolition. In fact, the Catholic just war tradition, in line with the above distinction between tranquillitas ordinis and shalom, generally imagines a world that approximates the eternal peace in the world to come, although it acknowledges that we will never achieve this end goal during our lifetimes. 36 Therefore, establishing and maintaining a tranquillitas ordinis, the peace of order, is seen as the objective of responsible statecraft. The idea of responsible statecraft was an important aspect in the previous Catholic interim ethic on nuclear weapons and should also guide the way forward in the grappling with Francis's immorality argument on both use and possession.
So what would a position on nuclear deterrence that is calibrated to the requirements of responsible statecraft look like? To answer this question, I draw inspiration from the argument made by Sagan in response to Nye's reasserted argument on nuclear deterrence. 37 Sagan has proposed five additional conditions on top of Nye's ten, which I welcome as important further restrictions. I am not suggesting that these five additions are all that is needed, but I believe they mark a step in the right direction. Firstly, Sagan calls for a nuclear doctrine that complies with the law of armed conflict and the jus in bello code of just war. Therefore, he wants nuclear powers to concentrate on counter-military and counter-leadership targeting, and rule out the targeting of enemy populations as part of a deterrence posture. 38 Secondly, Sagan advocates what he calls ‘the nuclear necessity principle’, which centres on the idea that nuclear powers ‘should not plan to use nuclear weapons against any target that could be effectively destroyed with conventional weapons and should use the lowest-yield nuclear weapon possible against the few deeply buried or hardened targets that could not be destroyed otherwise’. 39 Thirdly, Sagan wants to see an end to the concept of belligerent reprisal, the idea that in response to suffering an attack on one's civilian population, a nuclear power attacks enemy civilians in response. Fourthly, nuclear powers should only make nuclear deterrent threats as a response to being attacked with nuclear weapons themselves. In other words, policies of ‘calculated ambiguity’ that leave open the possibility of a nuclear response to conventional attacks should be abandoned. Finally, Sagan asks nuclear powers ‘to walk the walk, not just talk the talk’ when it comes to nuclear disarmament. Working toward progress in nuclear disarmament should be taken much more seriously.
Importantly, Sagan's final point, begging the question of how greater seriousness about nuclear disarmament can be achieved, leads to the specific contribution to which the Catholic conversation about nuclear weapons can contribute. 40 The first aspect I would like to highlight in this regard is the importance of moral witnesses. Listening to witnesses and learning from their experiences should be seen as an important pathway to reading the ‘signs of the time’ appropriately. Francis, in the speeches cited above, has pointed to the importance of listening to the survivors of the nuclear bombings of Hiroshima and Nagasaki. Familiarising ourselves with the immense destructiveness of nuclear weapons, and their long-term consequences, by listening to those who have had to live through these horrors should be a constant reminder to do everything that is possible not just to prevent another nuclear detonation, but to free the world of this danger once and for all. 41 In addition, there is much to be gained in learning from former key decision-makers who later on in their lives turned into nuclear abolitionists, or at least became proponents of large-scale nuclear disarmament. Arguably, these former officials, including George P. Shultz, Sam Nunn, and the late Henry Kissinger, exactly because they had been ‘Cold War warriors’, possess considerable credibility when they warn against the danger of these weapons. 42
Besides benefiting from the experiences of witnesses, there is another educational dimension that deserves close attention, namely, bringing to bear the resources of the Catholic moral tradition on nuclear questions. Scholars and educators working within the Catholic tradition should employ the resources the tradition hands to them to advance the goal of nuclear abolition. There are several areas where this can be done. One is the Catholic conversation about the ethics of war and peace itself. For example, the ongoing Catholic discussion between advocates of just war and just peace could be taken to develop the inherited tradition in response to new ‘signs of the time’. 43 Another is the field of professional military education. Being an educator in this field myself, I find it important to discuss the ethical challenges posed by nuclear weapons with military practitioners. Drawing on the Catholic conversation provides a rich foundation to grapple with these challenges. 44 Importantly, I would like to add, the Catholic conversation about the ‘immorality’ of both use and possession is relevant beyond Catholicism, and can inspire classroom discussions in diverse student bodies. Finally, more specific to practising Catholic soldiers, the military chaplaincies play an important role in accompanying soldiers, especially those in nuclear-related positions, as they discern the ‘signs of the time’. As nuclear ethics is highly complex, and Francis's ‘immorality’ argument on both use and possession has raised many questions about receiving it correctly, military chaplains need to make sure that soldiers have access to the spiritual accompaniment they need to carry out their roles as morally responsible practitioners.
Conclusion
Ever since John XXIII's powerful exclamation that ‘Nuclear weapons must be banned’, the Catholic Church has had a clear horizon for its nuclear ethics. A world that lives in genuine peace is not possible as long as nuclear weapons exist. The way toward nuclear abolition, however, is not straightforward. Responsible statecraft can be a very challenging undertaking that oftentimes makes very slow progress, and sometimes even requires detours. With his argument that both use and possession of nuclear weapons are ‘immoral’, Francis has contributed an important wake-up call to the conversation about nuclear ethics. As I have shown in this article, Francis's argument has received considerable attention from a diverse body of thinkers. Opinions on how to interpret his argument, especially regarding its practical implications, vary, and in this article I have added my own. These differing interpretations notwithstanding, what unites them is the belief that the ‘immorality’ claim provides a timely impetus to try harder to rid the world of nuclear weapons.
