A symposium contribution published on 1 October on the Nicaragua v. Germany proceedings before the International Court of Justice (ICJ) takes sharp issue with Germany's preliminary objection that advisory opinions cannot serve as a route around state consent in contentious cases. The author, Shahd Hammouri, a lecturer in international law and legal theory at the University of Kent and senior legal advisor at Law for Palestine, argues that Germany's position, while doctrinally intelligible, risks converting a procedural principle into what she calls "a doctrine of legal insulation."

The dispute centers on paragraph 189 of Germany's preliminary objections. There, Germany contends: "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."

Germany's argument, Hammouri concedes, has legal appeal. The ICJ is a consent-based court in contentious cases. Advisory opinions are not judgments between parties; they do not create res judicata and are not formally binding on states in the Article 59 sense. The distinction matters.

Yet the argument, in her view, moves too quickly from non-bindingness to legal irrelevance.

Consent versus jurisprudential authority

The crucial distinction, Hammouri writes, lies between formal binding force and jurisprudential authority. Advisory opinions do not bind states as contentious judgments bind parties. But they remain pronouncements of the UN's principal judicial organ on questions of international law. They clarify legal rules, identify legal consequences, interpret obligations and provide an authoritative account of a legal situation. The Court itself 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 recognition does not dissolve the consent principle, nor does it make advisory opinions an alternative route to a binding judgment. Rather, Hammouri argues, law's authority operates through more than one register: a pronouncement can be non-binding in a formal sense yet highly consequential in interpretative, institutional and political terms. Germany's paragraph, she writes, elides these registers by suggesting that any consequential reliance on an earlier advisory opinion in assessing admissibility would jeopardize consent. The real question is not whether an advisory opinion may be used at all, but how it is used and what the later court must decide.

The 2024 Advisory Opinion

The distinction assumes particular importance in relation to the ICJ's 2024 Advisory Opinion on Palestine, which Hammouri characterizes as concerning 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, she argues, effectively warns the Court against allowing this authoritative legal description to become too consequential when assessing the admissibility of a case concerning Germany's own conduct. The result is 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 characterisation is said to risk becoming too authoritative.

A TWAIL reading

Hammouri situates the argument within a Third World Approaches to International Law (TWAIL) framework, recalling a complaint she registered from a British international lawyer that Global South states are "'overdoing it' with those advisory opinions." Germany's formulation of consent appears universal, she writes, but formal universality can obscure unequal conditions of political and legal power. Historically, the consent principle protected sovereignty in an order in which sovereignty itself was unevenly distributed, and previously colonised states entered an international order whose central concepts — territory, statehood, jurisdiction, property — had already been shaped by colonial histories. Consent, she concludes, 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.

The logic of prevention

Hammouri frames the case as one concerning third-state responsibility and obligations owed to the international community as a whole. Nicaragua, she writes, asks whether Germany complied with its own obligations under the Genocide Convention, international humanitarian law and the legal consequences of serious breaches of peremptory norms — obligations she characterizes as prospective duties of prevention and due diligence, not retrospective duties triggered only after a conclusive judgment.

This does not reverse the burden of proof in a technical sense; Nicaragua must still establish the elements of its claims. But the nature of preventive obligations changes the inquiry, and Hammouri warns against a "lazy transposition" of criminal complicity doctrine to assessments of state responsibility. To demand a prior, substantive judicial proclamation of the underlying violations before preventive obligations become operational, she argues, would invert their temporal logic and make prevention dependent upon adjudication — even though adjudication often arrives only after the harm it is meant to avert has already occurred.

Practical stakes for practitioners

For practitioners, the piece crystallizes the core doctrinal question now before the Court in Nicaragua v. Germany: whether and how the 2024 Advisory Opinion may inform assessment of Germany's alleged breaches, and whether third-state obligations of prevention and non-contribution attach upon foreseeable risk rather than upon a final finding of responsibility against the primary actor. Hammouri's answer is measured. The proper response, she writes, is neither to deny consent nor to transform the 2024 Advisory Opinion into a binding judgment against Israel. It is to resist what she calls 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, she concludes. But they are not legally disposable. Germany's position, if accepted by the Court, would fortify stronger states seeking to refashion narratives of reality in pursuit of their own interests — and, in Hammouri's assessment, would undermine the Court's own authority.