The Justification of War and International Order – From Past to Present, Edited by Lothar Brock and Hendrik Simon (OUP 2021); Jacket image: Ingrid Krüger, Aquarelle, Tübingen 2002.

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Actions Speak Louder Than Words

Approaches to Justifying War Justifications


Few legal disciplines seem to manifest such a consistently discouraging discrepancy between the law in the books and the law in action as the international laws regulating the use of force between states. While in educated circles virtually no one concurs with the supposedly ‘realist’ claim that international law as a whole bears little to no impact on international relations, it cannot be denied that the specific field of use of force law warrants scepticism concerning its effectiveness. The de jure prohibition of the discretionary use of force, enshrined in the Charter of the United Nations, has coincided from the very beginning with a never-ending stream of violations, by authoritarian and democratic states alike.

Exploring this tension, the latest volume released in The History and Theory of International Law series sets out to study the historical narratives of justifying war and to make a case for public war justifications as useful sources for any legal-historical analysis on international order (p. 13). The thesis underpinning such efforts can be summarized easily enough: political actors – states, princes, naval captains – often put in the effort to justify their resort to force, as neglecting to do so might damage ‘his own standing in the existing communication community’, meaning that such discourses inevitably ‘interact with the international order’ (p. 4). The volume’s impressive list of 26 contributions thus contains a fair number that rely on analyses of texts justifying concrete uses of force – not just interstate war – compiled from the fifteenth century up until the present. This review focuses on contributions from Part III, on the international legal history of the nineteenth century, as well as the introduction and synthesis by the editors Lothar Brock and Hendrik Simon.

In The Trap of Presentism?

According to the editors’ introduction, the volume generally adheres to a genealogical approach (pp. 3-7), the meta-objective – at least for some of the authors involved – being to add a degree of historical legitimacy to the present-day use of force regime. At the same time, the two editors acknowledge that most of the legal-historical writing on the justification on uses of force thus far has concentrated on theoretical discourses, in the form of traditional doctrinal studies (p. 8). The editors explicitly recognize that such studies risk becoming ‘a-historical’ and need ‘historical and political contextualization (p. 9). This much appears as a measured approach, in line with Lauren Benton’s or Randall Lesaffer’s advice to respect historical context and historical evidence, to avoid any too obvious – or, conversely, any unacknowledged – cherry-picking. As it stands, however, these warnings are not always heeded.

With regards to the chapters on the nineteenth century, this has led to some bizarre statements. Isabell Hull’s chapter, for instance, argues, in line with her books, that Imperial Germany, more than any other state, violated in 1914 the then-existing laws of nations. While there is clearly a degree of truth to that statement – the violation of Belgian neutrality comes to mind – its conclusion seems exaggerated, as Miloš Vec already cautiously suggests in his chapter (p. 228). Hull bases much of her argument on the supposedly increasing legal containment of ‘aggression’ in the nineteenth century, which was ‘strongly suggested by state practice’, as found in the ‘rules’ of the Concert of Europe (p. 185). Hull’s indictment of Imperial Germany was largely achieved by defining aggression out of existence through a narrow, formalist definition of what constituted aggressive behaviour, bearing minimal resemblance to any common understandings, and largely drawn from a one-sidedly optimistic understanding of the Vienna settlement. It can hence be read that ‘no wars of aggression [were fought] on European soil from 1815 to 1914’; in fact, ‘there were few wars of any kind’ (p. 185).

According to this very bold claim, then, the following contemporary conflicts should no longer be seen as ‘aggressive’ wars: the two wars for Schleswig-Holstein, the Italian wars from the 1840s to the 1860s, the Austro-Prussian war, the Russo-Turkish war of the 1870s, the Greek war of independence, the Crimean war, the Franco-German war, or any of the interventionist crackdowns of revolution and civil war in Spain, Hungary, Poland, and elsewhere. In addition to this, there is a whole string of events that might fairly be characterized as aggressive, without having led to war: the Rhine crisis of 1840 or the Luxemburg crisis of 1867, Austria’s illegal annexation of Cracow of 1846, the bullying British ‘Sulphur war’ of 1840 against the Kingdom of the Two Sicilies, France’s occupation of Ancona of 1832, violating the sovereignty of the Papal States, or France’s blockade of Switzerland in the 1830s. Contemporary journalists could write, coolly, that ‘war remained the only final arbiter between sovereign states’.

Other scholarship paints a more pessimistic picture, such as Miroslav Šedivý. The argument would thus have been more convincing, had it also addressed the many, many instances in which ‘state practice’ looked like it cared little about Congress or Concert ‘rules’ whenever it clashed with state interests, of both great and minor powers alike. Particularly aggravating seems Hull’s exception for warfare when it was ‘tolerated’ for wars of unification, based on the principle of self-determination. This ‘exception’ – based on a naturalist principle in contradiction with Vienna’s positive principle of dynastic legitimacy – did not seem to have hindered most of the Concert ‘rules’ to have become widely accepted in state practice (p. 186). Yet it might equally be argued that Europe’s great powers merely accepted those ‘exceptions’ as deeply resented faits accomplis, which strongly contributed to the decline and fall of the Concert system, ripped apart long before 1914 in Europe’s vortex of nationalism, republicanism, liberalism, socialism, and imperial rivalries. The exceptions have swallowed the rule.

The Myth of The Myth

Closely aligned with Hull’s work is Hendrik Simon’s thesis on the ‘myth of liberum ius ad bellum’. A recent string of articles by Simon in prominent legal journals claims to have debunked the ‘myth’ that states in the nineteenth century were bound by few legal restrictions in the so-called ius ad bellum. In doing so, Simon boasts of having refuted ‘the overwhelming majority of recent literature’, including influential authors such as Martti Koskenniemi, Stephen Neff, and Wilhelm Grewe (p. 147). Not much can be held against this argument to the extent it deals with doctrine and theoretical discourse, as intellectual history. There can be little doubt that many within Western society during the nineteenth century felt a profound moral resentment to a more or less free right to go to war, a viewpoint that I also endorse in my own research on the international peace movement. That much is also in line with the existing literature on ‘just cause’ in early modernity, or with similar research by Agatha Verdebout. However, Simon – just like Hull and Verdebout before him – overstates his final conclusion, when he seeks to interpret state practice. Rather than reconstructing a lively intellectual debate in society, Simon wants to prove that there was real ‘normative progress’ – supposing interstate consensus – from which the ‘outright prohibition of the unilateral use of force slowly emerged’ (pp. 165-166). Simon calls this development the ‘birth’ of the modern war discourse (pp. 165-166).

The elaborate argument against this ‘myth’ starts in the French Revolutionary era and proceeds via the European Concert system to the Hague Peace Conferences of 1899 and 1907, interspersed with treatments of doctrinal authors. Much can be brought against the belief that any of these events and actors were sufficiently representative of contemporary international law – the interpretation of the European Concert System alone challengeable on the same grounds as above. However, the strongest and, to the author, most explicit example of ‘state practice’, analyses France and Prussia’s respective war declarations in 1870. Surprisingly enough, both sides claimed a just cause. From official statements such as these, the conclusion is said to be proven that ‘wars waged for the extension of a state’s position in the international system were seen as unjustified. State practice coincided almost ideally with the doctrine of bellum iustum’ (p. 159).

Bold claims such as these illustrate the pitfalls of neglecting contextualism for lawyers. After all, waging wars for the aggrandizement of the state was the hallmark of Otto von Bismarck’s brutal foreign policy of Blut und Eisen, which previously saw him engaging with the Danes and the Austrians in his violent bid for Prussian hegemony. It is a well-known historical fact that the French war declaration had been deliberately provoked by the Iron Chancellor – via a telegram consciously redacted to be more insulting to French pride – who correctly calculated that he would be able to count on the aid of the southern German states, and the non-intervention of the other great powers. Furthermore, the bulk of the war declarations in this century, when given, while certainly including some formulaic legal pleas, centred around national interests, barely masking naked self-interest under such euphemisms as ‘honour’ and ‘dignity’, or even ‘the glory of the state’. It is also usually impossible to view declarations from a strictly bilateral perspective: any claims inevitably touched upon the broader balance of power. Other states and the larger public could still think for themselves, and any propaganda victory for the issuing state could only be short-term. None of these reservations are refuted in the chapter. The war declarations themselves sufficed as evidence of ‘political practice’, although state practice was vastly more complex than a couple of propagandistic declarations. For reasons such as this, it seems unlikely that Simon’s thesis will be able to upend the established view, to the extent it wants to describe actual interstate normativity, rather than ‘just’ be an extensive and admirably well-done intellectual history – which is to be emphasized again.

Too Much Theory, Too Little Practice

One cannot simply pick up a few manifestos, along with a few other events, involving only a few states, and call it a day. Much more empirical evidence is needed before it can be reasonably held that any doctrinal book, or any official statement, corresponded to an actual, living, norm of generally accepted customary law in the international community. Importantly, any author seeking to tilt a long-standing conviction should make a conscious effort to convincingly explain how any deviating practice can fit into the desired new narrative, to disarm in advance any predictable – and inevitable – suspicions of selective readings of history and practice.

Much of this neglect may be found in the introduction, which reveals the limits of any discourse theory thus construed: the editors opted not to take into account an actor’s motives (p. 11). To contextualist historians, that is a huge handicap. From a lawyer’s perspective, it is akin to deliberately neglecting the legislator’s will, since in international law’s horizontal order, states are not only legal subjects but also law-makers. This returns us to the reservations expressed by so many with regards to use of force law. Koskenniemi’s thesis holds that any international legal argument oscillates between concreteness and normativity, between ‘apology’ and ‘utopia’. Lawyers who stick too close to state practice are seen as apologists of power politics, whereas idealistic lawyers are usually accused of interpreting the law as it should be, rather than how states practice it, relegating them to the foggy realm of utopian thinkers. Ultimately, any substantive conclusion remains elusive, and the lawyer essentially ends up articulating a political position through her or his legal argumentation.

Venturing on thinner ice, the position might be forwarded that some scholars investigating use of force law tend to advance ‘utopian’, largely acontextual, interpretations of international law, derived from questionable or limited interpretations of state practice, out of a – legitimate – concern to defend the modern-day legalist use of force regime, which is felt to be in danger. Unfortunately, this strategy runs the risk of straying too far from state practice. In this regard, the volume is aware the methodological criticism developed by authors like Clive Parry or Anthony Carty that opinio iuris is usually unknowable (pp. 8-9). However, these red flags are not incorporated enough, due to the belief that norms can be derived from public discourse alone. Perhaps influenced by the Nicaragua case’s ‘explicit objector’ rule – i.e. deviations strengthen the norm, if justified by invokingexceptions to that norm – several authors seem to assume that more weight should be given to a state’s purported opinio iuris, than to what it actually did. As contended by critics like Michael Glennon, however, this kind of thinking is circular and arbitrary. A state may indeed agree juridically with a rule that it violates, but it is likely more reasonable to conclude that a state disagrees with a norm it does not respect through its acts. Causation between opinio iuris and practice needs to be proven, not assumed. Modern practitioners often need to divine a state’s opinio iuris, out of pragmatism, since states keep their diplomatic archives under lock and key for many years. Legal historians, however, can and should look at the fuller picture, including internal memos, cabinet meeting minutes, diplomatic correspondence, and wider contexts, not seldom leading to more pessimistic, but arguably also more accurate conclusions as to the state of the law.

To the present volume’s credit: it does accept the existence of ‘multi-normativity’, described as ‘extra-legal spheres’, but this concept is not developed further beyond the rather innocuous premise that events usually have myriad causes, legal as well as extra-legal (p. 7). It should not be controversial to say that legal norms are typically only one aspect that goes into a state’s calculus of whether or not to act a certain way, besides other aspects like – in Glennons words – ‘the quality of a state’s leadership, the power of domestic constituencies, the structure of the international system, the state’s relative military and economic power, its “soft power”, and myriad other factors’. This is also taken for granted by academic historians.

Idealism Need Not Be Sentimentalism

None of what has been written above should be construed as ‘realist’ cynicism. Rather, the reflexions within this review merelyaim to underline the necessity of evidence-based empirical studies, aware of methodological limitations, and hesitant of too radical conclusions based on limited data. Restrained chapters by Miloš Vec, Aimee Genell, Mustafa Aksakal, and Lauren Benton do just that. Lauren Benton continues in her vein of ‘vernacular’ histories, using British naval captains’ logbooks and letters to the admiralty to argue that a perpetual right to use force ‘in small bursts’ existed in territories of so-called incomplete sovereignty (pp. 179-180). The chapters of Aimee Genell and Mustafa Aksakal, along with that of Miloš Vec, focusing on the First World War, both acknowledge that international law can ‘go dark’. This can happen because of great power predations, in the case of the Ottoman Empire (p. 218), or because of the duress of world war, as evidenced by the near-complete disregard of legal prohibitions on the use of poison gases between 1915 and 1918 (p. 237). More generally, these authors admit the fact that, while an international community without law is indeed unthinkable, the proper functioning of international law depends on underlying conditions that determine whether states can agree on certain norms. Many of these background conditions are strongly political in nature, yet not enough research has been done, either for today or for the past, into the reasons why states choose to create or expand international law, or, conversely, choose to ignore it. Even powerful states dislike international anarchy– contrary to some claims by ‘realists’. However, international lawyers still shy away too much from the often inseparable link between power and law, needed to understand both.

Justificatory discourses, in the past, but also in the present, can hence only provide partial indication of any opinio iuris,necessary not only to establish a customary law, but also to verify whether an actor truly believed to be acting according to law, or if this actor simply paid lip service to legal-discursive conventionalities to mask contrary politics. The words of the powerful need to be taken with a grain of salt. Failing to do so will likely land one firmly in some theoretical ‘utopia’, and be effectively counter-productive to the ideal of a just world in which the dogs of war are kept on a firm legal leash. Idealism need not be sentimentalism.

Wouter De Rycke

Wouter De Rycke is a PhD candidate at the Vrije Universiteit Brussel. He investigates legal discourse within the nineteenth century international peace movement (1815-1873).

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