No Peace without Justice,Just War as a Moral Frame of Reference

Introduction

The tradition of just war has been declared dead many times, but is still alive and kicking, even today. How is that possible, if most people in the world see war as an abomination, and strive for worldwide peace?

What can be said of just war? The presence of thinking on the justification of war in different world religions, philosophies and worldviews illustrates that its validity or lack thereof is neither derived from, nor dependent upon any religious consent; that it is not a comprehensive tradition on justice, peace and security, but only one paragraph in such theories and views; that, however, theorising on the justification of war in any variety still needs such a comprehensive theory, which is why it is at best a secondary theory. For this reason we will not speak of a just war theory, but of a just war tradition. ¹

The just war tradition appears in the most varied religions and political philosophies. Judaism, Christianity, Islam, liberalism, Marxism, all have variants of the just war tradition. How is this possible? The explanation is simple. It contains a set of moral ‘criteria’ that go back to a core question that each party asks itself on the eve of and during a military escalation of a conflict: In an inter-state conflict, can, may and should escalation to an armed conflict be undertaken, and if so, under what moral and ethical conditions?

In this contribution, to answer this question, we first outline the nature of the question of the justification of war. We then discuss two criteria from within this moral tradition: the legitimate authority and the just cause. This culminates in a discussion of a broad concept of justice, particularly in a Christian context. A broad concept of justice can offer a perspective on historical and social processes involving military practices. After a brief discussion of case histories in the field of just war, this contribution concludes with an evaluation of the just war tradition.

If the above question is reformulated, the moral tradition of just war is almost universal. It performs a heuristic function for any political government in conflict with other political governments and for churches seeking a tool to assess an impending conflict escalation from a moral perspective. Christian variants of just war are distinguished firstly by preceding ethics with theological virtues that link ethics with receptivity for transcendence: the divine gifts of faith, hope, and love.

A second feature is the distinction between just war on the one hand and holy war—with God as army commander—or religious war, war with the aim of securing the rights of the ‘true’ religion in a country, on the other hand. This, combined with a broad concept of justice, will be discussed below. A broad justice concept involves more than just the legality of military practices. Thirdly, just war is also distinguished in the Christian context by some degree of openness to Christian pacifism as a legitimate option for Christians, which goes back to the Sermon on the Mount (Matthew 5–7). ²

The Justification of War

In our opinion the question should be: Can, may or should an escalation of a conflict between states into an armed conflict be undertaken, and if so, under what moral and ethical conditions? Formulated thus, we immediately see three limitations of this tradition of just war. First, from a legal perspective, most armed conflicts are not wars. ³ Secondly, this tradition of just war does not contain any comprehensive ethics of international relations, but highlights one isolated paragraph. This immediately also exposes a third limitation: the tradition of just war in every philosophical and political variant is indebted to a more comprehensive theory of justice; without this, it is always a set of floating criteria that in fact determine the status of just war criteria which have the status of moral questions that always arise on the eve of wars: possibly pragmatic and useful, but not fundamental. The tradition of just war is, in other words, only a heuristic tool, at best a methodical tool for moral assessment, but certainly not a theory in the scientific sense.

The just war tradition is alive and well despite these considerable limitations. True, it is regularly invalidated. But nevertheless, it lives on. What is it all about?

Discussions of the just war tradition can be undertaken from different perspectives. The first perspective involves listing and describing the criteria (legitimate authority, just cause, exhaustion of peaceful means, likelihood of success, proportionality, non-combatant principle, right intention, principle of discrimination between civilians and military, principle of double effect, principle of proximate opportunity for evil). ⁴ It is possible to describe these criteria and then deductively apply them more or less systematically to a case. ⁵ It then appears whether—in the ius ad bellum—an intended war meets these criteria, or whether—in the ius in bello—it can be met or has been met. This always raises questions of interpretation: when are the peaceful means in a conflict really exhausted (not through lack of political will); how does one determine in advance the probability of success of a war; how is the proportionality of a war or act of war calculated?

A more subtle form of deductive application, the second perspective, takes place when, prior to the application of criteria to the case, a discussion takes place on how they can or should be updated. This occurs mainly in the case of two criteria: the ‘legitimate authority’ and the ‘just cause’. Regarding the criterion of ‘legitimate authority’, the UN Charter states:

Nothing in the present Charter shall impair the inherent right of individual or collective self-defence if an armed attack occurs against a Member of the United Nations, until the Security Council has taken measures necessary to maintain international peace and security. Measures taken by Members in the exercise of this right of self-defence shall be immediately reported to the Security Council and shall not in any way affect the authority and responsibility of the Security Council under the present Charter to take at any time such action as it deems necessary in order to maintain or restore international peace and security. ⁶

This thus confirmed the sovereignty of each member state, including the right to legitimate defence. ⁷ But at the same time, the power of states to legitimate defence is potentially limited once the UN Security Council has taken ‘necessary measures’. This implies that the UN Security Council is ultimately the supreme political authority on peace and security. This is a valuable fact, on the one hand, because it means that, as per the conclusion of Article 51 of the Charter, international security and peace can come first. But on the other hand, the effectiveness of the Security Council depends on consensus building, even among states with veto power. And this means that the UN Security Council can be a lame duck, as evidenced in the war over Ukraine: the Russian and Chinese have blocked condemnation of the Russian intervention in Ukraine. The effect of that blockade is that the legitimate authority in Ukraine, the government of that state, remains entitled to legitimate defence—and other states to support it. Incidentally, it is precisely for this reason that Russia argues that it is ‘denazifying’ Ukraine: in doing so, it presents the Zelensky government as an illegitimate authority, to be replaced. Either way: the ‘legitimate authority’ is a legitimate state. The legitimacy of a state becomes generally determined by the degree of sovereignty, integrity, effectiveness of the monopoly of force, and the quality of democracy and rule of law.

Security Dilemma

A guiding rationale in relations between states is the security dilemma: if, on the one hand, states arm themselves for defensive reasons, they may nevertheless be perceived as aggressive; if, on the other hand, they disarm themselves, they may actually become prey to another armed state. States are thus always faced with the task of balancing between the risks of an arms race and the risks of disarmament. ⁸

Ethically, this security dilemma is particularly meaningful. In both alternatives of the moral dilemma, states need the moral principle formulated by theologian and bishop Ambrose of Milan (340–397) of occasio proxima: one must not give another the opportunity for evil: every state must anticipate the potentially hostile behaviour of its adversary. ⁹ It is therefore not enough to pursue a policy of good intentions without paying attention to possible abuses of one's own actions by other states. Note that in the context of just war, the principle of occasio proxima implies the assumption that the acting party also has actual power and can exert influence on the adversary. In the case of utter powerlessness, akin to utter passive victimhood, this principle does not apply. Also, when handling the security dilemma, the principle of double effect is important: when pursuing political goals, one should not only consider and weigh the intended effects in the moral consideration, but precisely also the non-intended ones. In a military setting, this presupposes excellent strategy, doctrine, and planning. International law contributes—in compliance—to the predictability and calculability of risks associated with both poles of the security dilemma.

Regarding the criterion of the just cause, a no less important question arises as to how one defines it. The United Nations Charter offers a starting point. Article 51 of the Charter designates ‘international security’ as the benchmark for the UN Security Council. This presents it as a higher goal than the security of individual member states—although not a priori contrary to it. In addition, incidentally the Genocide Convention and more broadly the Responsibility to Protect provide for the right—or in the case of genocide, even the moral duty—to intervene. ¹⁰ As a result, the yardstick of international security is in fact also supplemented by humanitarian security of displaced persons and refugees. As a result, the security concept has become three-dimensional: international security, the security of states with their sovereignty and territorial integrity, and humanitarian security are seen as interrelated by the UN. This is a gain. But the question remains how security thus understood is related to justice. For justice is referred to in the concept of just war. In other words, the layered definition of security does not absolve one from the need to elaborate an ethical concept of justice.

In the discussion so far, we have implied that in the context of an ethics in international relations—of which just war as a contested discourse is a part—international law, including humanitarian and law of war, is part of a concept of justice. This choice is not without consequences for thinking about just war, as legal scholars argue that war has been prohibited in international law since the UN Charter. The UN Charter mentions, again in Article 51, only just defence. ¹¹

Here we encounter a moment of choice in political ethics: do we accept—in a Kantian logic—that international law (in this case the prohibition of war) succeeds and thus replaces ethics (in casu just war)? ¹² Or do we assume that international law also needs a moral and ethical foundation and legitimisation? The right-positivist current—which also exists in ethics—does the former: it assumes that law applies because it is there and not because or as long as it is deemed ethically acceptable. Natural law ethics and contract ethics do the second: they claim that law needs a ‘foundation’ or legitimisation, in the form of a normative-ethical, meta-legal ‘foundation’ or framing of some kind. ¹³ Depending on one's choice in this, Article 51 on legitimate defence by states thus expresses a substitution of just war or, on the contrary, a strict application of just war. On this, ethicists and jurists differ both among themselves and with each other. In either case, the connection with Article 51 ensures that just war is understood as an exception to the rule that waging war is not allowed unless in case of defensive action. The burden of proof thus falls on the moral acceptability of the exception.

Comparative Justice

Be this as it may, the concept of justice as understood in Western Christian traditions is not exhausted with the iustitia legalis. Justice has more elements. The first of these is iustitia commutativa: justice in reciprocal relations of citizens within a state and across state boundaries, including fairness in the conduct of trade, the obligation to honour contracts and the awarding of just wages to working people. Based on this principle, much could be said about North–South relations in the world.

The second element is iustitia distributiva: just distribution, an important principle from Christian ethics. This distribution of goods and services among all, according to the degree to which they are needed for a dignified life, concerns in fact everything that is conditional for moral good coexistence: from equal human rights for all people through equal opportunities in education and labour, for example, and a distribution of produced goods and services of which their actual allocation to the poorest is the measure.

This distributive justice is also at issue in the third element in the broadening of justice: the newcomer in ethics, climate justice, that is, the fair distribution of burdens and benefits in tackling climate warming. The causers of climate warming live largely in the rich north and west of the world, the people first affected by global warming in the south and east. The inclusion of climate justice in the concept of justice in the context of a just war deprives the rich North of the opportunity to legitimise wars caused by a lack of climate justice and distributive justice and which, as Pope Francis suggests, also fail to meet the standard of climate justice in execution. ¹⁴

The fourth element of justice in the broad Christian tradition is iustitia socialis, that is, proactive social justice—put forward for decades by the World Council of Churches and the Vatican. Development is the new name of peace, wrote Pope Paul VI. ¹⁵ This effectively overcomes a usual narrowing of justice to ex-post legal liability—after a wrong done; proactive responsibility is stronger than passive liability. ¹⁶

The fifth element in a Christian understanding of justice is the distinction between justice and justification: striving for justice is meaningful, but its moral and ethical significance cannot lead to self-justification in the form of self-legitimisation. From a Christian perspective, it remains necessary to have space to correct the self-justifying function of all ethics through a theology of God's gracious love. In any case, when such a layered understanding of justice, including the self-critical function of the difference between justice and God-granted justice, is brought into a public moral discourse concerning war for the purpose of testing whether in a case this war contributes to justice, we should note that the concept of justice requires comparison and appreciation of rights, interests, needs and requirements of all conflicting parties.

In other words, this leads to what is called comparative justice. ¹⁷ Without this procedural principle of comparative justice, the application of just war derails into self-justification in the sense of ideological self-legitimisation bordering on theological self-justification. By taking this comparative justice seriously, prosperous Europe does not get away with the fact that the test of whether a war is ‘just’ should only be about protecting ‘our’ prosperity and ‘our’ way of life.

This conceptual exercise on justice leads, by way of evaluation, to the conclusion that the question of the concept of justice in relation to just war is very important and certainly cannot be omitted when assessing the goals of a war, the just cause. The legitimate defence is a necessary but not sufficient part of a broader concept of justice.

By now, we have entered casuistry via the consideration of justice. This is no accident. The most frequent and, in some ways, the most persistent manifestation of just war is casuistry. ¹⁸ This makes sense. There is almost always a concrete historical and political reason to think about war as a moral possibility.

At the time of writing, these reasons are the war in and around Ukraine and the impending annexation of Taiwan by China. Case histories usually refer to just war in three ways. The first way is the rejection of this moral tradition: ‘wars can never be justified anyway!’ The assumption of this rejection of the tradition of just war is then that it would categorically justify wars and acts of war and that this tradition should therefore be rejected, in general and also in the present case. In our view, this rests on an error of reasoning: the just war is in fact nothing more or less than a moral frame of reference for judging wars and acts of war, and its application regularly leads to the rejection of war or moral criticism of acts of war.

An example to its use in moral criticism is the question of the proportionality and indirect effects of bombings like that on Hawija. ¹⁹ Regardless of what the outcome of this application is, it concerns a use of two criteria from the tradition of just war, namely proportionality and double effect. The second use of the tradition in casuistry is the adversarial: ‘this war (the case) cannot be just, because the violence of war is not proportional’. Here one derives from an element of tradition—the principle of proportionality—an argument against that same tradition. This ‘naïve’ adversarial critique of tradition is widespread in public opinion. The third way is the integration of a broad concept of justice, an updating of the criteria, and a careful application of the criteria.

Social Justice

Yet at this point in the argument, the question looms as to whether justice, as used in just war, is the supreme value. In any case, the pursuit of justice may also turn against the pursuit of peace. ²⁰ Could and should justice be pursued at all costs? That question is not purely hypothetical. For peace in the Christian traditions has more connotations than justice alone. Perhaps the most important of these is reconciliation. Again, this is a multi-layered concept. Theologically, of course, it also indicates the reconciled relationship between God and man in and through Jesus Christ. In Christian ethics, the concept of reconciliation refers to a situation after a conflict, in which renewed, restored, qualitatively acceptable relations are again possible. ²¹

This is important. In the post bellum situation, do former adversaries not only come into their own separately, but also in a constructive relationship with each other? From this point of view, as a complement to the ius ad bellum (the ethics prior to a war) and the ius in bello (the ethics during the war), the ius post bellum was also developed: an ethically sound ‘charcoal sketch’ of what post-war relations between conflicting parties should look like after the conclusion of peace as an additional yardstick for being allowed to go to war. ²² From here, an essential addition to and correction of the ius ad bellum took place. Parties must now, ethically, also anticipate the situation after a war—i.e., not only as an ‘exit strategy’ with a view to self-interest, but with a view for a common future with the adversary. In doing so, it must therefore be about more than legal redress: conflicting parties must be able to move forward together. This ius post bellum thus colours the ius ad bellum: without a future plan for reconciled relations, no just war. This is a widely shared consensus in circles of just-war theorists.

Of course, various elements of justice certainly play a role in reconciled relations, as can be seen in the processes of truth and reconciliation countries such as South Africa, Guatemala, Colombia, and Northern Ireland.

Apart from the ius post bellum it is important to prioritise the iustitia socialis. Social justice transcends legal justice. For the latter is usually reactive, in the form of liability after a crime. The first is proactive and provides the impetus to create more equitable socio-economic relations and to proactively distribute goods and services equitably. It is socio-economically and socio-ecologically relevant. In this way, social justice is the driving force behind iustitia distributiva, iustitia commutativa and the more recent climate justice. For peace, this is important because the hope attached to it is that more justice leads to fewer wars. As a result, at least the hope is that proactive justice is a route to conflict prevention.

Besides reconciliation, conflict prevention is the second pillar of the peace concept that complements justice. It has a strong relationship with proactive justice, but again it is broader. Conflict prevention also requires, for example, mutual investments in the economy of former arch enemies, legal mechanisms to settle disputes, and a system of sanctions prior to any armed intervention.

This is a line of thinking that we also see strongly expressed, for instance, in the encyclical Laudato Si’ by Pope Francis. ²³ In this encyclical he rejects future climate wars, arguing—at its core—that prevention of such armed conflicts can be achieved through what he calls an ‘ecological conversion’, of which climate justice is an essential part. Moreover, in Laudato Si’, conflict prevention is also always intertwined with sustainability and the affirmation of the intrinsic value of creation. In this context, an exclusive emphasis on justice can be criticised as inadequate anthropocentrism. These approaches to the just war from a broad concept of justice, from the ethics of reconciliation and from conflict prevention with a view to sustainability, are highly relevant for an evaluation of the just war. The question arises whether it has been superseded by an emphasis on conflict prevention and post-conflict reconciliation and by pointing to elements of justice other than iustitia legalis, of which legitimate defence is part.

Just Peace?

For some of the churches and theologians, these approaches to justice have been cause and reason to abandon the tradition of just war goodbye and to bet on just peace, a peace that is defined as the fruit of justice (Isa. 33:17).

In our view, this is a potentially legitimate attempt at a paradigm shift in thinking about war and peace. ²⁴ But that possible paradigm shift does not remove the need for an ethics of conflict escalation and of the process of de-escalation. A process ethics that interprets and tests conduct in the midst of contingencies and moral ambiguities remains necessary alongside a deontological ethics of principle and an ethics of purpose.

Such a frame of reference then offers not so much a picture of the good life and good conduct, but of the ‘right’ conduct. Seen this way, a moral frame of reference is needed precisely for this process. Not as comprehensive ethics, but by way of interim ethics. Whether one uses the frame of just war for this or not is a semantic issue in historical and social terms. A moral norm of conflict escalation, legitimate defence, but also of responsible, gradual, reciprocal simultaneous and verifiable de-escalation remains necessary.

This need lies in a ‘realistic’ assessment, based on the security dilemma of states, that in an ethics about peace one cannot assume that all people, let alone all leaders of states, are a priori ‘of good will’ and that a protection against evil in history—the war of aggression, genocide, the disenfranchisement of displaced persons, asylum seekers and refugees—is necessary. In other words, along the way to a just peace and the justice that just war aims at, one must continue to take into account the security dilemma and the ethical principles involved, in particular the occasio proxima and the double effect. With current knowledge, for example, it can be argued that by renouncing nuclear weapons, Ukraine acted not only unwisely but also morally wrongly, as it thereby lowered the threshold for military operations in the Donbas and later throughout Ukraine. The example is not accidental. Nuclear disarmament is very sensible, but it must always be two-sided, simultaneous and verifiable, precisely from the principles of the occasio proxima and the indirect effect.

Conclusion

From a reformulation of just war as an instrument with heuristic questions on the eve of and during wars, followed by a discussion of its limitations, we can conclude to the need for a broad concept of justice that is at least also developed from a Christian context. Having then connected the concept of justice linked to, in particular, peace, reconciliation and conflict-prevention, it appears that while this broadening may give rise to a paradigm shift from just war to just peace, in both cases it still raises the question of a process ethics, an interim ethics that does justice to the contingencies and ambiguities of historical-political situations in which armed forces operate, as needed, both to norm conflict escalation and to norm conflict de-escalation.

Church and theology have not needed to legitimise wars since 1648. ²⁵ They may do it, but they do not have to. Because states are sovereign and therefore secular, the laws of nations are in principle secular as well. But morality and ethics do set the stage for dialogue between church and state.

With that, even the just war is at most useful in a secularly-oriented political ethics, even if it is Christian-ethical in character. Church and theology can, may and must commend on just war from their Christian ethics, especially where, on the basis of their ecclesiology, the office of the watchman (Ezek. 33:7) is at stake, but should not confine themselves to a secular approach in fear of turning secular wars to religious wars: a political theology that takes the peace of Christ as its starting point is still as important. ²⁶ It constitutes, because it starts from a victim, a peace that takes seriously the evil in history and therefore—not in spite of it—renounces revenge and retribution, takes reconciliation and forgiveness seriously, and takes the most vulnerable as the measure of peace. It is at the same time—as peace of Christ in the genitivus subjectivus—already realised and—as peace in the genitivus objectivus—still incomplete, as long as it is not received and cannot be received in a world still fascinated, and partly controlled, by evil.

Therefore it was good that Ambrose of Milan was succeeded by his disciple Augustine of Hippo, who took seriously both the depth and the power of sinful evil, while simultaneously acknowledging the possibility of a anticipation of the peace of Christ, however limited it would be on earth. Thus it was possible for Augustine to thematise peace as part of personal and social life, while at the same time creating the possibility to use just war, not as a theory, but as an available moral frame of reference, that can be used in an ethics of conflict escalation. In short, there will never be real peace without real justice.

This article is based on a lecture, given in Nijmegen in the spring of 2023. Fred van Iersel sadly passed away in the summer of 2023. The reworking, editing and revising of the lecture into this article was therefore concluded by the second author, Bart van Dijk.