Quo Vadis? On the role of just peace within just war

Abstract

This article contributes to the debate about the future of just war thinking, which has been challenged by the emerging school of just peace. Just peace thinkers hope that by foregrounding nonviolent means just war reasoning will become obsolete. Recently, the German Catholic Bishops have argued that the traditional understanding of just war contributed to their predecessors' silence on the Second World War. Grounded in just peace thinking, their argument implies that had the new framework been in place at the time, it would have been easier for their predecessors to oppose Hitler's war. In this article, I defend traditional just war thinking as encountered in the thought of Thomas Aquinas. For Aquinas, just war thinking was part of an encompassing ethics of war and peace. In fact, peace was the primary goal. Grounded in Aquinas's understanding of virtue, I argue that there is a place for just peace scholarship within the just war framework. The tools of nonviolence should be seen as an important complement to the justifiable use of armed force.

The just war tradition has a remarkable pedigree during which it hardly ever remained static. Most often triggered by the changing character of war, thinkers, throughout the centuries, have sought to adapt the ideas of their predecessors in light of novel circumstances. In this process of renegotiation, the Catholic Church has been an enduring force. From the Church Fathers onward, the Church has exerted a profound influence on Western thinking about war and peace. Even in today's secularized world, the Church remains a potent participant in the conversation about the rights and wrongs of war. The Holy See frequently comments on questions of disarmament and arms control, and Pope Francis recently made an original moral argument by condemning both use and possession of nuclear weapons as immoral.¹ It is also noteworthy that Catholics are the strongest faith-based group in the US military. Thus, a change to Catholic teaching, such as Francis's recent rejection of nuclear deterrence, can have an impact on the world's leading military power.² Likewise, the election of President Biden, a self-professed devout Catholic who quoted Saint Augustine in his inaugural address and has placed a photograph of Francis in the Oval Office, suggests at least an indirect impact of Catholic Social Teaching on US foreign policy.³ Importantly, since the Second Vatican Council, Church leaders have commonly directed their remarks to ‘all people of good will’, seeking to enter into a conversation with the public sphere of civil society, rather than with faithful Catholics only. Their arguments, thus, provide a basis for a fruitful exchange about the ethics of war and peace, to which all citizens, believers, and non-believers alike, can contribute.

Not surprisingly, just as just war thinking generally has been adapted repeatedly, Catholic teaching on war and peace has evolved over the centuries. While its two historic default positions of pacifism and the acceptance of armed force within a dualism of permission and restraint continue to have a home in Catholicism, contemporary Catholic thinking on war and peace has been informed by a conversation about the right starting point of analysis. On one side of the debate, a majority of prelates and scholars advocates what they refer to as a ‘presumption against war’.⁴ These thinkers argue that before the use of armed force may be morally justifiable, a set of restrictive criteria must be met. By emphasizing the prudential criteria the just war tradition has developed, they want to make the resort to armed force exceptional. On the other side, one finds advocates of a ‘presumption against injustice’. These scholars, drawing on classical just war thinking, hold that the use of armed force remains a licit tool of statecraft to facilitate the goals of order, justice, and peace. They argue that the just war criteria should be calibrated in a way so that they can realistically be met. In other words, the purpose of the criteria is not to prevent war, but to use armed force, if morally justifiable, to address injustice.⁵

Before the horizon of this important debate, a novel ‘just peace’ project has emerged recently.⁶ Generally speaking, the contribution of just peace can be seen as an elaboration of the presumption against war view. Unlike pacifists, just peace scholars do not necessarily deny the morality of armed force per se, but they see the inherited just war teaching as neglecting the goal of peace. Their critique of just war revolves around two main aspects. First, they seek to make the use of armed force exceptional and, therefore, feel uneasy about the just war framework, which they consider to be too permissive. Second, just peace scholars seek to build a bridge between Catholic pacifists and just war thinkers by emphasizing tools of nonviolence. Prominent supporters of the just peace project have been the German Catholic Bishops. They recently published a document in which they reflect on their predecessors' unwillingness to oppose German aggression in the Second World War.⁷ In their view, just war teaching was one explanatory factor for the failure to delegitimize Hitler's war and the Bishops point to the just peace framework as a lesson to be learned from history. The outcome of the debate about the future of just war and the role of just peace matters not only for Catholic thought, but also for the course of normative International Relations generally. It is to be expected that, as has historically been the case in many areas of just war thinking, the conversation about just peace that has emerged within Catholicism will soon extend to the wider normative debate on war and peace.

Reflecting on the example of the German Bishops, I seek to animate a conversation between just war thinking and the novel just peace framework. I will argue for a continued role of just war thinking as part of an encompassing ethics of war and peace. Without a doubt, investigating nonviolent peacebuilding should be seen as a laudable undertaking. Just peace scholars seem to strike a nerve by noting that just war thinkers' focus on the use of force may not give due attention to the transformative potential of nonviolent tools. However, against just peace scholars, I assert that there is no need to replace the just war framework. Drawing on Saint Thomas Aquinas, the arguably most influential classical just war thinker, I hold that there is a place for nonviolent peacebuilding within just war. For Aquinas, peace was the horizon of any just use of force. The sovereign's responsibility to establish justice included both the nonviolent reduction of structural violence, the main objective of just peace, and the use of force to maintain or establish peace. I will demonstrate that while in his writing the latter aspect dominates over the former, Aquinas's understanding of virtue is open to moral progress and, therefore, can accommodate an elevated engagement with nonviolent tools. In other words, just peace scholarship can enrich just war thinking from within and there is no need to replace just war with a new moral framework. In this context, I will also argue that Francis's recent decision to no longer use the term just war should not be seen as a break with the core idea of the just war tradition, namely, that the use of armed force can be morally justifiable if certain criteria have been met. Throughout, I will highlight the German contribution that has been influenced by the nation's militaristic past as uniquely capable of pointing to the challenge of finding the right equilibrium between permission and restraint regarding the use of force.

In terms of outline, the article starts off with an overview of the just peace project. Providing a critical appreciation of just peace, the article, then, argues for the continued viability of the just war framework. It does so by engaging with the German Bishops' assertion that the traditional Catholic understanding of just war partly explains why their predecessors did not oppose Hitler's war. Drawing on Aquinas, the article demonstrates that traditional just war teaching could have been employed to delegitimize German aggression. In fact, Church leaders, including the pope and leading German Bishops, referred to Aquinas when they, covertly, supported attempts to assassinate Hitler. The article goes on to argue that it was not the traditional just war teaching that prevented a no to Hitler's war, but rather the unwillingness to apply it faithfully due to mainly prudential reasons. Thus, the German Bishops' intimation that just peace would have made it easier to delegitimize German aggression fails to convince; a just war analysis provided all that was needed to ‘speak truth to power’. Subsequently, the article turns to nonviolent peacebuilding as a pillar of just peace. Affirming the transformative potential of nonviolent tools, the article argues that such means can have a place within just war thinking. Revisiting Aquinas's ethics, the article shows that although his discussion of just war concentrates on the use of armed force, his treatment is part of an encompassing ethics of war and peace. Moreover, Aquinas's account of the virtues is open to development. Thus, his just war may be complemented by nonviolent peacebuilding and the article illustrates how this can be done vis-à-vis the contemporary Catholic presumption against war view.

The case for just peace

Just war thinking has received an ambiguous treatment in contemporary Catholic Social Thought, culminating in Francis's recent decision to no longer speak of just war: 'A war is always - always! the defeat of humanity, always. ... There is no such thing as a just war: they do not exist!'⁸ At the same time, however, the pope at least indirectly affirmed Ukraine's right to self-defense against Russian aggression. This tension between rejecting war and accepting defensive uses of armed force should come as no surprise as, throughout its history, advocates of nonviolence and the morally justifiable use of armed force have had a home in the Church. Historically speaking, Catholic pacifists can claim that the early Church, before Christianity became the state religion of the Roman Empire, had overwhelmingly advocated nonviolence. Even in times when the popes themselves waged war, the Church included powerful pacifist voices. Simultaneously, for a majority of contemporary Catholic advocates of the core just war idea, the nature of modern war requires a pendulum swing back in the direction of the Church's pacifist roots. Having experienced the destructiveness of modern warfare in conflicts such as the Franco–Prussian War and, later on, the two World Wars, Catholic leaders increasingly came under the impression that war could no longer be waged with restraint. The threat posed by nuclear weapons further contributed to the adoption of what today is known as the presumption against war view. Within this frame of a general skepticism toward the moral justifiability of armed force there has been another important recent debate. A ‘just peace’ school has emerged that ‘focuses on what causes conflict and therefore sees peacemaking as the ever vigilant effort to establish justice’.⁹ Just peace thinkers hold that just war too willingly justifies the use of force and, simultaneously, criticize pacifism for its failure to appreciate the realities of international politics.¹⁰ Just peace, according to Lisa Sowle Cahill, gives ‘almost exclusive priority’ to nonviolent peacebuilding and, unlike just war, its focus is not on ‘delineating exceptional situations where violence might be justified’.¹¹ The immediate origins of just peace thinking go back to the Gulf War when Protestant Christian ethicists led by Glen Stassen sought to find what might be imagined as ‘connective tissue’¹² between pacifism and just war.¹³ Engaging with this foundation and drawing on the general development of Catholic thought on war and peace sketched above, Catholic just peace scholars emphasize nonviolent peacebuilding that also addresses cultural and social violence as a viable alternative to the use of force.¹⁴ The hope and expectation of just peace thinkers is that the role of just war thinking ‘will become increasingly marginal to the positive advocacy of peacemaking or peacebuilding’.¹⁵ They question whether the contemporary trajectory of Catholic thinking on war and peace teaching should still be seen as an alteration of just war and suggest to take up the just peace framework as a means of ‘ethical collaboration under a bigger umbrella’.¹⁶ Cahill, who imagines just peace as ‘the rightful heir of Christian just war and pacifism’,¹⁷ argues that the two Catholic default positions ‘must yield’ to just peace, which she describes as ‘more pragmatic, realistic, and appropriately ambiguous’.¹⁸ In the context of just peace, the tools of nonviolent peacebuilding have at times been discussed within the jus ante bellum ¹⁹ (right before war) and jus post bellum ²⁰ (right after war) categories. Both categories seek to create circumstances in which the use of armed force can be circumvented. In other words, they are meant to avoid triggering or returning to considerations of jus ad bellum and jus in bello; jus ante bellum; and jus post bellum, just peace thinkers hope, will prevent the outbreak of war.²¹ In practical terms, the tools of nonviolence are plentiful, including, for example, mediation efforts, demobilization, development of infrastructure, post-conflict reconciliation, and human rights promotion.²²

To date, there has been no consensus about the future of Catholic just war thinking generally and the role of just peace specifically. Whilst it is likely that the term just war will no longer be employed in Church documents after Francis's recent decision to stop using it, its continued place in academic debate, which is the main concern of this article, seems secure. Within the German context, the post-war consensus about military restraint as a consequence of the nation's militaristic past seems to have contributed to the German Bishops' enthusiasm for just peace thinking.²³ In addition, in A Just Peace, the Bishops seek to draw lessons from the first decade following the Cold War that saw the Gulf War, the violent dissolution of Yugoslavia as well as ‘a whole series of bloody conflicts’ that they consider to be indicative of ‘a seemingly insurmountable system of wars’.²⁴ The Bishops' lesson learned is to adopt the just peace framework. While not discounting just war reasoning as such, the Bishops do not seek to salvage the framework by arguing for an ever more restrictive version of it. Rather, the idea of just war as a useful basis for arguing about the restraint of war is deliberately moved into the background.²⁵ Crucially, in line with the emphasis on jus ante bellum and jus post bellum action, the document's section on practical means shows a clear hierarchy in which the exceptional use of force is discussed last.²⁶

I suggest that the Bishops' skepticism toward just war helps explain their standpoint that the traditional just war teaching contributed to their predecessors' silence on the Second World War. Their recent statement was drafted under the leadership of the German Justice and Peace Commission, which has been a fervent advocate of just peace. While not denying the morality of war altogether, the German Bishops imagine just peace as a deliberate counterpoint to traditional just war teaching. In this sense, the recent statement on the Second World War can be read as an attempt to delegitimize the just war framework. Consider that the Bishops, in the document's concluding section entitled ‘Lessons for the Future’, insinuate that had the just peace teaching been in place at the time, it would have been easier for their predecessors to say ‘no’. In their own words, by adopting just peace, they have been able ‘to make the central insights of the doctrine of a “just war” … applicable in such a manner that they do better justice to the intention of containing violence’.²⁷ Having situated the German Bishops firmly within the just peace camp, the following section will take a closer look at their engagement with the role of their predecessors during the Second World War. This will set the scene for the subsequent argument in favor of the continued viability of just war and the attempt to theorize about the proper place for just peace thinking.

The German Bishops on the Second World War

In late April 2020, in the week before the 75^th anniversary of the end of the Second World War, the German Bishops published a document in which they engage with their predecessors' attitude toward Hitler's war. Noting that taking judgment on their predecessors would not suit them well the Bishops seek to draw lessons for the present and future by learning from history.²⁸ The Bishops argue that their predecessors ‘share in the guilt for the War, given that the bishops did not say an unambiguous “No”, but that most of them strengthened the will to persevere’.²⁹ Regarding the question of why their predecessors did not speak out against the war the Bishops identify seven factors: (1) the traditional teaching on the legitimacy of state authority and the Church-state relationship, (2) the traditional teaching on just war, (3) the acceptance of society that the presence of the military in everyday life was natural, (4) the relationship between the Catholic Church and the German nation, (5) the fundamental rejection of communism, (6) the specific conditions and experiences of the National Socialist era, and (7) the institutional weakness of the Bishops’ Conference and its internal blockage.

The Bishops begin their discussion of state authority by noting that their predecessors' thinking had been characterized ‘by traditional ideas of order which originated in Ancient philosophy and theology, and which interpreted and shaped the world of the Middle Ages’.³⁰

… the Church viewed state powers and physical force as being given and desired by God. This did not rule out criticism of those who were responsible. The order was however not questioned per se, since resistance to the state order was simultaneously understood as resistance to the divine will. … After the seizure of power by the National Socialists, whose ideology the bishops clearly rejected, the German State was hence still regarded as a force for order which had to be respected and protected.³¹

With regard to just war teaching, the Bishops note that while their predecessors did not legitimize Hitler's war as a just war they, following the traditional understanding, ‘called on soldiers and the faithful to be loyal, to carry out their duty, to prove their value, to atone and to be willing to make sacrifices’.³²

This doctrine, which can be traced back to Cicero, Augustine and Thomas of Aquinas [sic] … – in contradistinction to its intention of limiting violence – had increasingly become a means of legitimising physical force in the modern era, and had contributed towards people becoming accustomed to the use of violent means. Even if doubts had became [sic] louder since the experiences of the First World War as to the established political approach towards this doctrine, it nonetheless contributed to the vast majority of Christians not yet fundamentally questioning war as a form of political conflict in the first half of the 20th Century.³³

While the Bishops are correct that their predecessors did not unambiguously condemn Hitler's war, the first two explaining factors on their list are less convincing than they suggest. The reason for this is that the final five factors can be substantiated based on empirical evidence, whereas the theoretical considerations captured under the first two factors do not seem to be as straightforward.³⁴ In the next section, I engage with the present-day Bishops' two theoretical explanatory factors as to why their predecessors did not speak out against Hitler's war. I argue that traditional just war teaching could have been employed to delegitimize the war. As the Bishops explicitly refer to Aquinas, one of the key figures in classical just war thinking, I employ his thought to back up my argument.

Just war and the challenge of speaking truth to power

Aquinas's succinct account of just war is ideally positioned to analyze the Bishops' critique of traditional just war thinking.³⁵ Aquinas's three criteria of sovereign authority, just cause, and right intention directly correspond to the Bishops' explaining factors of state authority and just war. Importantly, while concentrating on Aquinas, I do not seek to suggest that his thought is solely representative of classical just war. Additionally, I do not propose that all of his medieval thought, parts of which strike us as morally indefensible today, should be taken to enrich today's debates. However, the work of Aquinas is of particular importance for the tradition as he systematized the classical just war by bringing together various streams of thought ‘which had been shaped by philosophical, theological, and political thinking on natural law, by military thought and practice, by legal traditions reaching back into Roman law, and by accumulated experience in the government of political communities’.³⁶ Aquinas developed his argument by dialectically linking his own position to the particular opinions of his predecessors, including Cicero and Augustine, the other two just war thinkers the German Bishops have singled out.³⁷ Aquinas's own position on just war would become the authoritative statement that later thinkers used as a foundation for their own arguments.³⁸ To name only one example, Aquinas's fellow Dominican Francisco de Vitoria, by some credited as the ‘Father of International Law’, is commonly referred to as a Thomist for the influence Aquinas's thinking had on his own.³⁹

Sovereign authority

The following section provides an account of sovereign authority as found in the work of Aquinas. Its first part engages with the authority to wage just war; its second part tackles the question of when a sovereign may be removed. Thomas listed the authority criterion in first place vis-à-vis the question of when it is justifiable to go to war.⁴⁰ James Turner Johnson argues that Aquinas's conceptualization should be seen before the horizon of the medieval understanding of the sovereign as being responsible for ‘the vindication of justice in the service of good order and peace for the community’.⁴¹ Consequently, because only the sovereign was entitled to decide on the matters of just cause and right intention, sovereign authority was the primary criterion of just war, logically prior to the other criteria. Johnson identifies two directions from which the leading role of the authority criterion resulted.⁴² The first is the argument that only sovereign temporal rulers had the right to use armed force. It was the sovereign's responsibility to maintain or work toward peace imagined as tranquillitas ordinis, or the tranquility of order. Consequently, for Aquinas, the sovereign's authority to use the sword was inseparably linked to his/her responsibility for the common good.⁴³ The second direction Johnson identifies is the reflection about sovereign rule as ‘essentially moral in character, requiring virtue on the part of the ruler’.⁴⁴ Medieval accounts such as Aquinas's commonly referred to Romans 13:4 which defined authority, including the authority to use force, as having been bestowed upon the ruler by God. In addition, the passage also had significance for the character formation of the good ruler because the ruler, defined as ‘minister’ of God, had to acquire the necessary virtues.⁴⁵

While there is a scholarly consensus that Aquinas put considerable trust in the authority of the sovereign, it needs to be noted that Johnson's interpretation has recently been challenged by Gregory Reichberg, who does not support the idea that sovereign authority is conceptually prior to the other just war criteria. Importantly, Reichberg's argument relates to the German Bishops' debatable reference to Aquinas as source for their predecessors' silence regarding the Second World War. Johnson has been a long-time critic of the predominant contemporary Catholic interpretation of just war. Following his reading of Aquinas, Johnson suggests that because the sovereign is the one charged by his/her office with discerning just cause and maintaining right intention, Bishops should be careful not to overstep their authority when making public announcements on war and peace. Reichberg, in contrast, is of the opinion that Johnson exaggerates the significance of the authority criterion in Aquinas's thought, arguing that Johnson ‘attributes to him a position that was explicitly developed only later by some Spanish scholastics’.⁴⁶ The disagreement between Johnson and Reichberg is highly relevant for this article because it might be taken to explain why the German Bishops did not confront Hitler on foreign affairs while, in a remarkable contrast, some of them forcefully spoke out against internal wrongdoing such as the regime's euthanasia policy. One possible explanation for this contradictory behavior might be that the Bishops, following the later reading of Aquinas that Reichberg identifies in Johnson's work, deemed internal matters more within their purview:

In line with their endorsement of Hitler's foreign policy, the German bishops seem not to have raised the question whether a war waged for the Führer's expansionist aims would be just or unjust. They taught the faithful to be prepared to serve the fatherland, and Archbishop Gröber added that Catholic theologians had ‘never left it to the judgment of the individual [Catholic], with all his shortsightedness and emotionalism, in the event of war to decide its permissibility or lack of permissibility. Instead, this final decision has always been in the province of the lawful authority’.⁴⁷

However, as the following section demonstrates regarding the related issue of violent resistance, Aquinas's original conceptualization of authority did not emphasize the role of the sovereign in such a way that subjects had no authority to challenge their ruler.

Sovereign authority, disobedience, and tyrannicide

For Aquinas, based on the ruler's responsibility for the common good, sovereign authority went beyond the mere possession of power. Sovereign authority, in order to be legitimate, had to be assumed and carried out lawfully.⁴⁸ In Aquinas's own words: ‘Illegitimate is that which is against the law’.⁴⁹ Moreover, in line with the sovereign's task of creating the conditions for a collective life of virtue, Saint Thomas held that rulers ‘ought to be virtuous themselves, and their initiation of war should flow from a choice that is inwardly regulated by the appropriate virtues. By the same token, the obedience which is due to these leaders on the part of the citizenry must itself be tempered by virtue’.⁵⁰ Naturally, Aquinas thought that only virtuous sovereigns were entitled to demand virtuous behavior from their subjects. In consequence, although Thomas did not explicitly mention the concept of selective conscientious objection, it seems fair to assume that he would have argued that soldiers had a moral obligation not to fight in wars that were clearly unjust.⁵¹ Later thinkers, including Vitoria and Suárez, would discuss the extent of the right, and even the obligation, to dissent from a ruler's decision to make war and to refuse to take part in such a war.

Going one step further than advocating resistance to fight in unjust wars, Aquinas also had something to say about the morality of removing a tyrant.⁵² Following his grappling with ‘the tension between submission to the state and the protection of the public good’⁵³ that is inherent to the issue of tyrannicide, he accepted that it could be justified to remove a tyrant, either from the outside by neighboring princes, or from the inside following a just resistance. How far Aquinas was willing to go with regard to the latter instance has been subject to debate, as his position on tyrannicide varies according to which of his works is consulted.⁵⁴ In fact, Aquinas does nowhere explicitly affirm a right to kill a ruler, perhaps due to the influence of the nonresistance texts set forth in the New Testament.⁵⁵ However, ‘although his thoughts concerning tyrannicide may seem fragmentary or tangential, or both’,⁵⁶ it seems fair to conclude that he, too, accepted the concept that a tyrannical ruler should be opposed, removed from office, and possibly killed. This is a position commonly associated with John Calvin, but it appears also in Aquinas on the nature of tyranny and how to deal with it.⁵⁷

Sovereign authority and Hitler

Based on what Aquinas had to say about state authority, are the German Bishops correct to state that the traditional Catholic understanding made it difficult to speak out against Hitler? To begin with, it needs to be noted that, in contrast to the Nazi party's own claims, Hitler's Machtergreifung was by no means a seizure of power. Rather, Hitler assumed the chancellorship lawfully. Thus, although he had been outspoken about his totalitarian and inhumane ideology, his government was, at least initially, a sovereign authority in the Thomistic understanding. However, as Hitler solidified power and implemented his immoral policies, he clearly turned into a prototypical tyrannus in regimine,⁵⁸ a ruler who legitimately came to power but turned into a tyrant later. I do not seek to make an argument here about when exactly Hitler ceased to be a legitimate sovereign, but I hold that he certainly had turned into a tyrant by the time the war broke out. Moreover, he did in no way exhibit the virtues Aquinas expected from a just ruler. From a Thomistic point of view, it seems more than questionable that he still had the moral authority to wage war at that point. Later on, especially after the German invasion of the Soviet Union, there could no longer be any doubt about the nature of the regime's aggression. In addition, those who wanted to know knew about the systematic persecution and murder of the Jews and other groups that was ongoing meanwhile. And, in fact, the Church, from the German Bishops up to the pope, were well informed about both Hitler's criminal war and the ongoing genocide.⁵⁹ Furthermore, beyond denying Hitler the right to wage just war, the Thomistic account also could have been taken to justify killing Hitler, as, remarkably, actually was the case. As Mark Riebling shows in his study of Pius XII, the pope was involved in three plots to assassinate Hitler.⁶⁰ Crucially, for the argument of this article, these attempts at tyrannicide had the support of the German Bishops and were justified in reference to the thought of Aquinas.⁶¹

In conclusion, there is nothing in Aquinas's thought that would have prevented the German Bishops from denying Hitler the authority to wage just war, nor of ruling out his removal, even his violent removal, in principle.⁶² As the historical record shows, it was mainly prudential reasons that caused the Catholic Church, including the German Bishops and the Holy See, to keep a low public profile in its opposition against Hitler, while simultaneously conducting covert action.⁶³ As far as just war thinking is concerned, Hitler's failure to meet the threshold of sovereign authority would by itself have been sufficient to deny him the right to wage just war. From a Thomistic point of view, for a war to be just the trinity of just war criteria must be met. Thus, the following argument that Hitler's war also violated the criteria of just cause and right intention should be taken as further evidence that the inherited just war teaching did provide the critical eye to speak truth to power.

Just cause and right intention

In addition to sovereign authority, Aquinas spelled out the criteria of just cause and right intention. In this section, I demonstrate that although the German Bishops are correct that the just war of classical thinkers like Aquinas had a less restrictive attitude to the use of force than most contemporary accounts, Hitler's war would have violated both just cause and right intention classically conceived. Saint Thomas defines just cause as follows: ‘Secondly, a just cause is required, namely, that those who are attacked, should be attacked because they deserve it on account of some fault’.⁶⁴ For Aquinas, just war served the function of ‘vindicative justice’⁶⁵ and he did not list the self-defense rationale in his discussion because he considered it to be an inherent right of both individuals and states. In this regard, Aquinas's just war deviates markedly from the almost unanimous consensus in contemporary just war thinking about self-defense as the prototypical just cause for war. Having said that, Aquinas's embrace of punishment notwithstanding, there has been no consensus about the question of whether desert should be a just cause for war. While the retributionist reading of Aquinas has historically been dominant, the brevity of his account also allows for a liabilist reading that was introduced by Vitoria and elaborated on by Luis de Molina.⁶⁶ For the purpose of this article, I concentrate on the retributionist reading as it seems fair to assume that the German Bishops have this more permissive interpretation in mind when they point to the ostensibly missing restraining function of traditional just war teaching.

Aquinas developed his idea of retributive war in parallel with his thought on the death penalty.⁶⁷ As Brian Calvert demonstrates, Saint Thomas's argument on the death penalty shows all the main features of retributivism: he holds generally that a crime deserves to be punished and in order for that punishment to be just, a crime must actually have taken place and the criminal suspect must have committed the misdeed. In addition, the wrongdoer must have been a responsible agent at the time he/she committed the crime.⁶⁸ These last two aspects are supposed to ensure that only the guilty are punished. Furthermore, Aquinas's account of retribution argues that crime and punishment must be proportionate, and he follows retributive theories in the assumption that a crime caused an imbalance in the order of justice, which a justly imposed punishment aims to correct.⁶⁹

With regard to the criterion of right intention, Aquinas's understanding holds that intention in war shows in belligerents' war aims and how they fight to achieve those. In other words, right intention ‘gives concrete shape to the condition of just cause’.⁷⁰ For Aquinas, right conduct in war is inherently connected to the ‘virtuousness of its purpose’.⁷¹ That is why he, quoting Augustine, cautions against beginning war for other than virtuous intentions as well as the negative passions which can arise on the battlefield. Moreover, Aquinas also directly connects right intention to the goal of peace, imagined as the (re)establishment of order.⁷²

In summation, Aquinas allowed two just causes for war, namely, retribution and self-defense. Importantly, for a war to be just, the criterion of right intention had to shape the just cause. In order to act with a right intention, both sovereigns and soldiers had to act virtuously, which would require avoiding the negative passions that tend to arise in war. Right intention also naturally demanded the goal of peace. Through the emphasis on virtue, Aquinas connected the right intention criterion directly to the requirement of sovereign authority, which also demands virtuous behavior from the sovereign.

Hitler's war: just cause and right intention

In a sense, investigating the morality of Hitler's war is an odd task given that, as Brian Orend notes, ‘World War II, on the part of the Allies, is the definitive modern example of a morally justified war, at least in connection with jus ad bellum’.⁷³ If one accepts Orend's assertion, then, from a Thomistic point of view, Hitler's war had to be unjust. The reason for this is that Aquinas's just war builds on the notion that a party is legitimized to wage war only if those whom it attacks ‘deserve it on account of some fault’. In other words, the unjust side, at least objectively speaking, cannot have just cause or right intention to fight back. Having said that, despite the strong consensus about the unjust nature of Hitler's war, it is worth considering how the German Bishops regarded, or could have regarded, the situation at the time.

I start my discussion with the just cause of self-defense because it is the easiest to refute. Simply put, there were no grounds for Germany to describe the Second World War as a war of self-defense. In actual fact, holding that view would let the observer buy into Hitler's justification for the initiation of the war when he argued that the attack on Poland was a legitimate act of self-defense aimed at protecting Germans who had been prosecuted within Poland. While early just war arguments in support of Germany may be excused due to the so-called ‘fog of war’, the Fulda Bishops Conference published pastoral letters until 1943. Thus, at least at a later point, the Bishops knew about the falseness of Hitler's claim of self-defense. It should also be noted that jus ad bellum considerations are not to be understood as applying solely at the beginning of a war. These considerations are meant to be ongoing judgments to be made as long as the war lasts. Unfortunately, I do not have the space here to provide a detailed analysis of the war. What I do want to argue, however, is that as the war spread, first to the West and, then, to the Soviet Union, it had to be increasingly clear that Hitler did not fight defensively. In the West, there had been no manifest threat to German security. While France's Maginot Line resembled a strategy of defense cast in concrete, Hitler himself repeatedly mocked the UK government for its appeasement policy and the US remained committed to its Neutrality Acts. In the East, the Soviet Union constituted an ideological rival that, at some point in the future, may have threatened the Reich, but the 1941 invasion could in no way be portrayed as an act of self-defense. Last but not least, as Riebling's research suggests, the Church, by the help of its network of spies in Germany, had always been on top of developments and, in fact, the Holy See warned the Allies of the imminent attack in the West.⁷⁴

The just cause of retribution provides more food for thought. It should be remembered that the Treaty of Versailles imposed terms on Germany that the majority of Germans considered to be unjust. In fact, there seems to be a consensus among historians that Hitler's promise to undo the Treaty of Versailles was one of the main driving forces behind his rise to power. Before I begin my reflections, however, I need to emphasize that Pius XII no longer embraced the classical conceptualization of war as a form of punishment. Consequently, the ‘traditional teaching on just war’ that ostensibly prevented the Bishops from speaking out against the war had already been limited to legitimate defense at the time.⁷⁵ Importantly, the German Bishops arguably found the so-called Diktatfrieden [peace dictate] to be unjust and worthy of revision. As they put it in their 1933 pastoral letter, the first pastoral published after Hitler's rise to power: ‘We regret that the victorious nations, in blinded selfishness, have suppressed justice and, through a tremendous burden put on German shoulders, have increased the manifold misery from which we have been suffering up to intolerability since the end of the war’.⁷⁶ While the Bishops go on to state that they are not calling for an ‘unchristian policy of revenge or even an upcoming war’, they demanded ‘justice and living space in the interest of universal peace’.⁷⁷ As a consequence of Versailles, Germany had lost a seventh of its territory and a tenth of its population. Given that Aquinas emphasized the retributive just cause, would not a war aimed at returning the ostensibly unjustly seized territories have been justified?

The answer has to be ‘no’ following from both Aquinas's conceptualization of retribution and the moral movement imposed on the just cause of retribution by the criterion on right intention. As noted above, for a punishment to be just, crime and punishment must be proportionate. In other words, the just cause of retribution would have ceased to exist after having returned to the status quo ante.⁷⁸ However, for Hitler, the war was never about re-establishing an equilibrium of justice. Otherwise, he would have limited his conquest in the West and would not even have started Operation Barbarossa in the East. As far as the Bishops are concerned, then, it had to be clear to them in 1941 at the latest that Hitler's war did not meet the just cause criterion. In addition, the criterion of right intention also shows that Hitler's war was no war of retribution. Modern just war thinkers commonly dismiss the just cause of retribution as they find it impossible to distinguish between just retribution and unjust vengeance.⁷⁹ However, while getting this distinction right is admittedly challenging, Aquinas, through his stress on virtue, held that it can be done.⁸⁰ That is the reason why he warned of the negative passions arising in war and pointed to the goal of peace. Recalling the negative passions listed by Aquinas, Hitler's treatment of right intention seems like a caricature of a leader who had internalized those illicit motivations. His disregard of right intention could easily be identified in both his words and deeds and needs not be spelled out further here. I leave it at noting that the Bishops were more than aware of Hitler's malevolent intentions when they, as early as 1933, warned of an ‘unchristian policy of revenge’.⁸¹ Likewise, a war of aggression of such magnitude was diametrically opposed to the goal of peace.

Concluding this section, there can be no doubt that Hitler's war was unjust as seen from a classical Thomistic perspective. The war failed all of Aquinas's three just war criteria. It is also worth emphasizing that the Bishops at the time secretly supported three tyrannicide attempts against Hitler, and grounded their action in the thought of Aquinas. The real driving force behind their predecessors' silence on the war, as the contemporary Bishops note elsewhere in their document, was the concern of being prosecuted even more harshly by a regime that considered Catholicism as one of its main ideological adversaries. Thus, in contrast to the suggestion made by the Bishops, the traditional Catholic teaching could have been employed to speak truth to power and it was a prudential decision to protect the Church that prevented the faithful application of just war thinking. Having said that, as the next section will argue, just peace thinkers are right when they assert that, in traditional just war teaching, nonviolent peacebuilding did not receive the attention it arguably deserves. Rather than replacing the just war with a new framework, however, I will argue for complementing the traditional understanding of just war with the tools of nonviolence. Drawing on Aquinas's account of the virtues that is open to development, I explain how nonviolent peacebuilding can make a valuable contribution to just war thinking without compromising the continued justifiability of armed force.⁸²

On the place of just peace within just war

When thinking about Aquinas's just war it is crucial to consider his conceptualization before the horizon of his understanding of virtue. I cannot provide a detailed discussion of his complex understanding of virtue here.⁸³ What I can do, however, is provide a discussion of the interplay between the cardinal virtue of justice and the theological virtue of charity, which, I will argue, provides an opening to complement traditional just war thinking with the tools of nonviolence. Rosemary Durward summarizes my idea succinctly: ‘… through a systematic analysis and integration of philosophy with theology, he [Aquinas] confirmed and emphasised aspects of a just war tradition that would have significance not only for a just war but for the idea of a just peace’.⁸⁴ The essential difference between the cardinal and theological virtues is that the former primarily inform earthly human action, whereas the latter guide humankind to the supernatural end of beatitude, which, for Aquinas, is defined as unity with God.⁸⁵ In other words, the theological virtues, and charity as the highest of them, help human beings approximate the end of beatitude in this world.⁸⁶ With regard to just war, finding the right balance between considerations of justice and charity constitutes a challenge. It is a challenge that is also manifest in Aquinas, who discussed just war in the section on charity. Reichberg suggests that Aquinas sought to avoid treating just war under the rubric of justice because he did not want to concentrate on the punitive dimension. However, it is important to note that Aquinas did not imagine just war as an act of charity specifically. What he did was establish an indirect connection between just war and charity that characterized just war as a reactive use of force capable of being both protective and restorative.⁸⁷ In consequence, there is arguably no reason to assume that charity applies to just war differently than it would apply to any other human action. Likewise, just war should not be seen as an act of charity as such although, as Reichberg notes, Aquinas's argument does not seem to foreclose either interpretation.⁸⁸

Elsewhere I have argued that the virtue of charity may be seen as an important force behind Catholicism's increased skepticism toward just war, which has been epitomized in the debate about a presumption against war and that lies at the heart of just peace thinking.⁸⁹ Johnson has criticized that view, arguing that the historical starting point of thinkers like Aquinas had been a presumption against injustice, which did not consider the use of force to be justifiable in exceptional circumstances only.⁹⁰ Johnson was later vindicated for his argument about a presumption against injustice as the original starting point of Aquinas.⁹¹ Even J. Bryan Hehir, a key contributor to the 1983 US pastoral, acknowledged that Johnson had been right about the original starting point.⁹² However, Hehir argued that just war thinking was open to development and the presumption against war should be seen as an adaptation of the inherited teaching to the changed character of war. I have argued that contemporary Catholic thought has been giving special attention to charity in how it sees the need to establish justice in this world, which results in the conceptualization of war as so exceptional that it can hardly ever be just. That said, I think that both presumptions can claim a home within Thomistic thought.⁹³ Their main difference is that they disagree about the extent to which armed force is justifiable, which is arguably informed by a different estimate about the interplay of charity and justice in contemporary international affairs. None of the two positions rejects the use of force per se and, thus, both have a place within just war.⁹⁴ In consequence, exactly because both presumptions can be rooted in Aquinas, his thought provides fertile ground for a conversation about when armed force should be used. While the two sides will find the other's interpretation either too permissive or too restrictive, Aquinas's classical argument can animate a thought process about whether, say, a particular humanitarian intervention is morally justifiable. At the same time, both sides will be able to draw on Aquinas to enrich just war thinking with nonviolent peacebuilding.

In this context, it is important to contextualize Francis's recent decision to no longer use the language of just war. In 2016, a conference on ‘Nonviolence and Just Peace’ was held in the Vatican, organized by the Justice and Peace Commission and Pax Christi. The conference called on Francis to abandon just war in favor of just peace.⁹⁵ The pope himself had approved of the conference and sent a brief reflection on the importance of nonviolence, without showing acceptance of just peace.⁹⁶ Subsequently, however, there had been suggestions that Francis might break with just war.⁹⁷ In the context of the war in Ukraine, the pope eventually decided to take this step. However, he also at least indirectly affirmed Ukraine's legitimate right to self-defense. Consequently, Francis rejects the term just war without embracing a pacifist position. Moreover, whilst being sympathetic to the tools of nonviolence, the pope has not officially adopted the just peace framework. As a result, he continues to support the core just war idea that armed force can be morally justifiable within a dualism of permission and restraint. The break with just war is thus mostly a semantic one that marks the climax of a development that started with the advent of modern war. All modern popes have emphasized the condition of war as an evil, because any war comes with the killing of innocent life. When Francis rejects the possibility of a just war, he has in mind that even a country like Ukraine, who has a legitimate right to self-defense, has been drawn into the moral evil that is war. Another element in his rejection of just war is the distancing from the earlier, more permissive modes of just war that the Church no longer accepts. In that sense, the pope's decision to break with just war partly echoes the position of the German Bishops I have investigated above. Whilst the intention to avoid giving legitimacy to war is most laudable, however, without embracing pacifism the task of arguing about when armed force can be morally justifiable will remain. This is the task that for centuries has inspired the just war tradition and to which I turn to now regarding the place of just peace within just war.

In the following concluding section, I will present the thought of Aquinas as capable of facilitating a conversation between the classical understanding of just war that the German Bishops reject and the novel just peace approach. In particular, I hold that Aquinas's thought can help find the right balance between armed force and nonviolence that informs the most recent conversation about the merits and limitations of just war. Having argued that both versions of Aquinas's just war have a place for nonviolent peacebuilding, what would be the contours of a presumption against war framework that is enriched by just peace thinking? To begin with, as part of the sovereign's responsibility to facilitate order, justice, and peace, nonviolent peacebuilding would be seen as an inherent aspect of his/her job description. As noted earlier, Aquinas argues in his discussion of right intention that any just war must intend the goal of peace, and this peace must be one that reestablishes justice. Just war, that is, must aim at a just peace. For Aquinas, questions of war and peace were irreversibly associated. Additionally, as noted above, Aquinas links the virtue of charity, the highest virtue, and the imperfect peace of human existence. The virtue of justice takes on only a mediate function in this conceptualization.⁹⁸ For the temporal order this could mean that the sovereign's task should include building a just and sustainable peace by, for example, reducing cultural and social violence. Moreover, as part of his/her responsibility for the common good of his/her own and of neighboring polities, the sovereign should also seek to reduce structural violence abroad. In this sense, addressing concerns such as illicit arms trade, human trafficking or climate change could all be parts of a Thomistic just war framework. Consequently, grounded in charity, the nonviolent peacebuilding contemporary just peace thinkers foreground can have an important place in Aquinas's ethics. In fact, according to Reichberg, the linkage of just war to peace might have been another reason why he discussed war in the section on charity: ‘Just as bellum iniustum is a grave violation of temporal peace – the naturally good concord of nations – in like manner, its opposite, bellum iustum, must contribute toward maintaining the peace, or toward reestablishing a peace that has been disrupted’.⁹⁹ In Aquinas's own words: ‘Those who wage war justly aim at peace, and so they are not opposed to peace except to an evil peace, which our Lord “came not to send upon earth”’.¹⁰⁰

Applying Aquinas's thought to the idea of just peace as unfolding within just war, Mark Allman and Tobias Winright provide a helpful image. Referring to considerations of jus ante bellum and jus post bellum that are central to just peace they speak of the ‘growing edges of just war theory’.¹⁰¹ Their hope is that the just war tradition will be ‘telescoped in both directions, and should integrate jus ante bellum and jus post bellum considerations with the standard jus ad bellum and jus in bello categories’.¹⁰² Regarding the presumption against war view, the contribution of just peace would be to point to the potential of nonviolent tools to establish states of justice that both prevent war and, in the aftermath of war, usher in a just peace. At the same time, the use of armed force remains a morally justifiable option of last resort when nonviolent tools fail to bring the desired outcome and an expansive list of criteria is met. In the longer term, the just peace inspired presumption against war view would hope to continue growing the edges so that the core of just war thinking, the use of armed force, would be needed less and less frequently.¹⁰³ This is how I understand Francis, his rejection of the term just war notwithstanding, and, to my mind, it also constitutes a reading of Aquinas that is reconcilable with the position held by the German Bishops.¹⁰⁴ It should be remembered that the Bishops have not ruled out the use of force in specific circumstances. While they did not sanction the 2003 Iraq war,¹⁰⁵ which some imagined as a humanitarian war, they supported military action in other cases, such as Kosovo,¹⁰⁶ the fight against ISIS¹⁰⁷ and, most recently, affirmed Ukraine's right to self-defense against Russian aggression.¹⁰⁸ A comparison of the Iraq and Kosovo cases reveals the crux of the presumption against war vs. presumption against injustice debate at the beginning of the 21^st century: What should be the right balance between permission and restraint vis-à-vis the use of force for humanitarian causes? In contrast to some presumption against injustice scholars, the German Bishops did not consider the humanitarian cause to be sufficient to justify the war in Iraq.¹⁰⁹ The Bishops did not buy into the argument for regime change that, as advocates argued, was underpinned by the desire to establish justice.¹¹⁰ Doubtlessly, the Bishops' skepticism toward too permissive a moral framework is rooted in German history. In fact, their rejection of the Iraq war reflected the mainstream opinion in both the public sphere and academia at the time.¹¹¹ However, despite a societal consensus about military restraint, the Bishops, 5 years earlier, had supported humanitarian intervention in Kosovo. Thus, the Kosovo case illustrates how the ideal of nonviolent peacebuilding can come under pressure.¹¹² It marks a case, as does the fight against ISIS and Ukraine's defense against the Russian invasion, where the Bishops accept the use of armed force despite their strong presumption against war and the hope to transcend the use of violence, which are the backbone of just peace. Grappling with the classical argument of Aquinas, I believe, can remind just peace scholars that there will be cases where force may be used, while, at the same time, giving due emphasis to nonviolent peacebuilding. It also provides a strong case against abandoning the just war idea that is built on the dual theme of permission and restraint.

Conclusion

Just war and just peace scholars have in common the goal of creating a more just and peaceful world. The notion that the term just war should no longer leave our mouths as easily as in the past is understandable. No person of good will advocates war for war's sake. In addition, as the example of the German Bishops during the Second World War demonstrates, while just war thinking does provide the criteria to distinguish a just from an unjust war, that is no guarantee that the criteria are employed faithfully. However, the latter is a determination that applies to all non-pacifist moral frameworks, including a potentially independent framework of just peace. Just war and most just peace thinkers agree that the use of armed force can at times be justifiable. Their main point of disagreement is about when, not if, the use of force can be morally defensible. That is why I have argued in this article that both have a home in just war thinking imagined as an ethical framework that builds on the dual theme of permission and restraint. The just war framework can accommodate the presumption against injustice and the presumption against war under one roof. Moreover, both presumptions have a place for just peace thinking. Bringing the classical thought of Aquinas to the conversation can help both sides identify the right circumstances where force may be used, while seeking to build a world of justice that does not require the use of armed force in order to establish order and peace.