Symposium on Jurisdiction, Responsibility, and Temporality: Nicaragua v. Germany Before the ICJ – Insulating Legal Reality? Assessing Germany’s Position on the Relevance of Advisory Opinions

[Shahd Hammouri is a lecturer in international law and legal theory at the University of Kent, and a senior legal advisor at Law for Palestine. She is the author of Corporate War Profiteering and International Law (CUP, forthcoming 2026).]

Germany’s insistence that ICJ advisory opinions cannot become a route around consent in contentious proceedings is doctrinally intelligible. But its argument risks turning the formal distinction between advisory and contentious jurisdiction into a means of insulating legal reality from the material reality that international law has itself helped name. In the context of Palestine, that move has particular consequences: it transforms the non-binding form of an advisory opinion into a reason to discount its authoritative description of an ongoing structure of occupation, dispossession and domination. 

Paragraph 189 from Germany’s preliminary objections states:

Consent is the essential basis for the exercise of the Court’s jurisdiction in contentious cases. It would be both contradictory and destabilising if the fundamental requirement of consent in contentious cases could be bypassed by reference to past advisory proceedings in which consent was an irrelevance precisely because such proceedings were only of an advisory character and therefore were of a different nature and served a different function. The result would be that findings made in an advisory opinion could no longer be characterised as ‘only of an advisory character’ and of ‘no binding force’.

The claim has some legal appeal. The International Court of Justice is a consent-based court in contentious cases. Advisory opinions are not judgments between parties; they do not create res judicata, and they are not formally binding upon states in the Article 59 sense. The distinction matters.

Yet the argument moves too quickly from non-bindingness to legal irrelevance. It treats any consequential reliance upon an advisory opinion as though it necessarily converted that opinion into a contentious judgment against a non-consenting state. That is not the only possibility, and it is not how international adjudication ordinarily works.

Consent and the Authority of Advisory Opinions

The crucial distinction is between formal binding force and jurisprudential authority:

Advisory opinions do not bind states in the same manner as judgments in contentious proceedings. But they are still pronouncements of the UN’s principal judicial organ on questions of international law. They may clarify legal rules, identify legal consequences, interpret obligations, and provide an authoritative account of a legal situation. The Court regularly treats its prior judgments and advisory opinions as part of its jurisprudence, even though Article 59 rejects a formal doctrine of binding precedent.

This point does not dissolve the consent principle. Nor does it make advisory opinions an alternative route to a binding judgment. It simply recognises that law’s authority operates through more than one register. A legal pronouncement can be non-binding in a formal sense yet still be highly consequential in interpretative, institutional and political terms.

Germany’s paragraph elides these registers. It suggests that, if the Court in a later contentious case were to rely on the legal conclusions of an earlier advisory opinion in assessing admissibility, the consent principle would be jeopardised. But that conclusion does not follow. The question is not whether an advisory opinion may be used at all. It is how it is being used, and what the later court must decide in order to resolve the case before it.

The Reality that the Advisory Opinion Describes

That distinction assumes special importance in relation to the 2024 Advisory Opinion. The Opinion is not simply an abstract restatement of legal rules. It concerns a material and institutional reality of grave violations of international law: the illegal occupation of Palestinian territory; settlement expansion; territorial fragmentation; annexationist policies; apartheid and systemic racial discrimination; violations of sovereignty over natural resources and the forceful obstruction of Palestinian self-determination.

Germany’s objection effectively warns the Court against allowing this authoritative legal description of reality to become too consequential in deciding on the admissibility of a case concerning Germany’s own conduct. The danger of this logic is that the Court’s most careful legal account of an unfolding situation of grave illegalities affected millions is placed in a sealed doctrinal compartment – available to advise a UN organ, but unavailable, or only weakly available, when assessing what other states knew, what obligations they possessed, and whether they discharged them.

This produces a striking juridical asymmetry. International law may identify a situation as unlawful in advisory proceedings, but when a state’s conduct is challenged in contentious proceedings, that legal characterisation is said to risk becoming too authoritative. The concern for consent can become a mechanism through which international law’s own authoritative recognition of reality is rendered practically inert.

A TWAIL Reading: Consent, Sovereignty and Selective Realism

Reading Germany’s argument, I recalled a complaint I registered from a British international lawyer once: states of the global south are ‘overdoing it’ with those advisory opinions, we must find a way to stop them. 

Germany’s formulation of consent appears universal: all states, equally, are protected from unwanted contentious adjudication. But formal universality can obscure unequal conditions of political and legal power. Historically, the consent principle has often protected sovereignty in an international order in which sovereignty itself has been unevenly distributed. Colonial powers exercised decisive control over colonised peoples without their consent; mandates, protectorates, concessions and imperial interventions frequently took legal form without meaningful participation by those whose territories and futures were governed. Previously colonised states and peoples then entered an international order whose central concepts, territory, statehood, jurisdiction, property and development, had already been shaped by those histories. 

The Palestinian case lays bare this tension. Palestinian self-determination has repeatedly been affirmed in the language of international law. Yet the mechanisms through which that right might be realised remain mediated by the sovereignty, consent and strategic choices of other states. Israel’s policy in Palestine is predicated on mass-coercion, and the prevention of any expressions of collective will in the form of consent or resistance. An advisory opinion can articulate the legal consequences of an unlawful situation. But a contentious case concerning a third state’s alleged support for that situation may encounter doctrines designed to prevent the Court from determining the responsibility of the state whose conduct forms the underlying condition.

The issue is not that consent should be discarded. The issue is that consent cannot be treated as an innocent procedural baseline when it structures access to legal remedy in a world marked by radically unequal capacities to create, resist and evade legal accountability.

International Law and “Reality”

The deeper question raised by Germany’s submission is what international law means when it speaks of “reality.” International law commonly presents itself as a discipline of facts: territorial control, military operations, arms transfers, official statements, treaty commitments, governmental knowledge and causal contribution. But it also creates the legal categories through which those facts become intelligible.

International law does not merely observe the world from outside. It helps organise the world it claims to describe. It classifies populations, allocates territory, stabilises property claims, regulates violence, distinguishes lawful from unlawful authority, and authorises or limits intervention. The legal distinction between an advisory opinion and a contentious judgment is therefore not a technical detail outside politics. It shapes what kinds of reality can become actionable, against whom, and in what institutional form.

This is why the non-binding character of advisory opinions cannot settle their significance. The Court’s advisory opinions may be legally non-binding, but they can reveal a contradiction at the heart of the international legal order: the system may be capable of naming illegality while lacking, or declining to exercise, mechanisms that make such naming consequential for powerful third states. In the context of a globally catastrophic failure of third-state responsibility to prevent and end a live-streamed genocide, accepting this doctrinal insulation bears structural risks to the survival of the international legal system.  In other words, validating Germany’s logic would undermine the court’s own authority. 

The danger is not simply that advisory opinions are accorded too much authority. The danger is that their authority, especially when used by weaker states, is recognised only in a ceremonial or declaratory register. They may function as what international law is willing to say about the world, while contentious jurisdiction is confined to what international law is institutionally willing to do about it.

A Closer Look at the Logic of Prevention

This case should be understood, first and foremost, as one concerning third-state responsibility and obligations owed to the international community as a whole. Nicaragua asks whether Germany has complied with its own obligations in the face of grave and widely documented risks that bear consequential effects for international peace and security: obligations arising under the Genocide Convention, international humanitarian law, and the legal consequences of serious breaches of peremptory norms. The central question, as ascertained in Nicaragua’s oral pleadings, is therefore not simply whether Israel’s responsibility can be definitively proclaimed in Germany’s absence, but whether Germany was entitled to continue acting as it did while the relevant risks and legal warnings were already apparent.

The gravity of the alleged violations is significant to the legal analysis. Where there is a serious risk of genocide or of other grave violations of international law, the relevant obligations are not merely retrospective duties triggered once a court has issued a conclusive judgment. They are prospective obligations of prevention and due diligence. Their purpose is to require states with knowledge, influence or material capacity to act before irreversible harm occurs. Under this logic, the state bears the responsibility of demonstrating that it has taken reasonable measures, within its capacity, to ensure that its assistance, cooperation and external relations do not contribute to prohibited conduct and that it uses available means to prevent or mitigate violations.

This is not a reversal of the ordinary burden of proof in a technical sense. Nicaragua must still establish the elements of its claims. But the nature of preventive obligations changes the relevant inquiry and warns against lazy transposition of legal thought pertaining to criminal complicity or personal responsibility to assessments of state responsibility. Coherence demands that these legal arenas are treated philosophically and theoretically distinct. The question is not confined to whether a completed internationally wrongful act has already been judicially established against the primary actor. It is also whether, in the presence of a serious and foreseeable risk, Germany undertook the diligence required to discharge its own autonomous obligations. A state cannot plausibly treat uncertainty about a final finding of responsibility as a licence for inaction where the very point of the obligation is to prevent catastrophic harm before it becomes legally irreparable.

This is particularly important because the duties at issue are intended to safeguard international peace and security through peaceful, preventive and cooperative means. They require states to assess risk, exercise influence, suspend or condition support where necessary, and take practical steps to prevent the escalation or continuation of grave illegality. To demand a prior, substantive judicial proclamation of the underlying violations before these obligations become operational would invert their temporal logic. It would make prevention dependent upon adjudication, even though adjudication often arrives only after the harm it is meant to avert has already occurred.

The consequences of that approach are not distributed equally. Powerful states may have the diplomatic, military and institutional resources to shape legal narratives, delay accountability and withstand the political consequences of uncertainty. Weaker states, peoples under occupation, and communities experiencing mass violence rarely enjoy comparable access to international adjudication, diplomatic protection or law-making power. A doctrine that insists on definitive judicial confirmation before third states must take preventive obligations seriously therefore risks reproducing existing inequalities within the international legal order.

Germany’s reliance on the distinction between advisory and contentious proceedings should thus sound the alarm. Advisory opinions are not binding judgments. But they may nonetheless provide a highly authoritative account of the legal framework, the nature of the situation and the obligations that arise for third states. The question is not whether the Court should use an advisory opinion to bypass consent. It is whether Germany, in light of the information, legal findings and risks available to it, fulfilled its own independent duties of prevention, due diligence and non-contribution.

Conclusion

The proper response to Germany’s argument is neither to deny consent nor to transform the 2024 Advisory Opinion into a binding judgment against Israel. It is to resist the false choice between formal bindingness and legal significance.

Advisory opinions are “only advisory” in the sense that they do not bind states as contentious judgments bind parties. But they are not only advisory in the weaker sense of being legally disposable. They are authoritative juridical accounts of international law and, in this case, of a protracted political and material reality. Germany’s position risks converting a procedural principle into a doctrine of legal insulation one that prevents the Court’s own account of an unlawful reality from informing the assessment of states that materially support, benefit from, or possess influence over that reality. In other words, Germany is asking the court to overlook the reality of a well-established record of grave violations of international law against one of the world’s most precarious nations. If the court were to accept this argument, then it is fortifying the authority of stronger states seeking to refashion narratives of reality in pursuit of their own interests.