Serena Forlati, Makane Moïse Mbengue, Brian McGarry

The Gabčíkovo-Nagymaros Judgment of 25 September 1997 is one of the most influential pronouncements of the International Court of Justice (ICJ) and brings to the forefront the complex relationship between the two main functions of the Court: namely, deciding ‘in accordance with international law such disputes as are submitted to it’ as set forth by Article 38 of its Statute; and contributing through its case law to the development of international law.

The ICJ took a rather unusual approach to the settlement of the dispute submitted to it and was not completely successful in this respect. Indeed, some commentators argue that the ambiguity of the Court’s findings lies at the basis of the Parties’ inability to definitively settle their disagreement ¹ – although a number of other factors explain why the lengthy post-judgment negotiations have led only to Slovakia withdrawing its request for an additional judgment on issues of execution, ² but not to a settlement of the main case, which is still formally pending after more than 20 years.

At the same time, the Judgment also adopted important stances on various complex environmental law issues and on delicate problems of ‘general’ public international law. Among other aspects, it significantly contributed to the elucidation and consolidation of a number of legal rules pertaining to the law of treaties, the law of international responsibility and their mutual relationship. While the relevance of the case in this regard was immediately apparent, the importance of its legacy has become clearer over time, with its key findings being upheld not only by the ICJ in its later case law or by the International Law Commission, but also by States and by other international courts and tribunals.

This book aims to offer an all-around analysis of the Judgment as regards both the case as such and the main substantive legal issues at stake. The contributors attempt a reappraisal of the Court’s findings in light of subsequent developments of the international legal order, also addressing the role of the ‘World Court’ in fostering such developments.

Part 1 focuses on the case as such: Alain Pellet, who was successively retained as counsel by both Slovakia and Hungary, offers a personal recollection of the case and suggests that the Court, having in fact fulfilled its function, should remove it from the docket. Malgosia Fitzmaurice explores the background of the case, the complexity and sensitivity of which are among the reasons why the underlying dispute is not completely settled yet. Jean d’Aspremont then analyses how the Gabčíkovo-Nagymaros Judgment used the International Law Commission’s (ILC) work on international responsibility – and, in turn, the Judgment’s impact on the Articles on Responsibility of States for Internationally Wrongful Acts (ARSIWA) – in order to discuss the ‘symbiotic relationship’ between the ICJ and the ILC in the construction of general rules of international law.

Laura Pineschi’s introduction to Part 2 on the Law of Treaties takes a critical look at the Court’s failure to provide a solution that the Parties could implement, discussing whether the ICJ actually used all available means under the law of treaties to settle the dispute and whether the law of treaties in itself is a suitable framework for the purposes of effective settlement of international environmental disputes. Christina Binder and Jane Hofbauer then address the approach of the ICJ to the interpretation of treaties; they specifically consider how the tool of evolutive interpretation may make it difficult to identify the borderline between the correct application of the pacta sunt servanda principle and (inadmissible) forms of judicial revision of treaties – while also criticizing the little guidance offered by the Court as to how the Parties should implement their obligation to negotiate a concerted way out of the impasse caused by their reciprocal violations of the 1977 Treaty. Panos Merkouris delves into the treatment by the Court of issues relating to the termination of international treaties, recalling that the Judgment dealt with several grounds of unilateral termination set forth in the Vienna Convention on the Law of Treaties, in a case which did not fall under the scope of the Convention as such; the main contribution of the Court in this respect is thus the clarification as to the customary status of those rules, which was not seriously put in question by later practice.

Part 3 on the law of international responsibility opens with the remarks of Alessandra Gianelli, who puts the Judgment’s findings in this field in its historical context, notably with reference to the work of the ILC on the law of State responsibility. The relationship between this branch of international law and the law of treaties is addressed by Serena Forlati, discussing the ICJ’s key findings – on both the mutual autonomy and functional interaction between the two regimes – and their impact on later case law and practice in different areas of international law. Pierre Bodeau-Livinec then analyses the treatment of circumstances precluding wrongfulness, notably necessity and countermeasures, providing further insight on the ‘constructive dialogue’ between the ICJ and the ILC in this specific context. On the other hand, Loris Marotti and Paolo Palchetti discuss the innovative and case-specific treatment of remedies in Gabčíkovo-Nagymaros, which explains the case’s relatively limited influence specifically as regards the consequences of internationally wrongful acts. At the same time, the Court’s approach finds an echo in the flexibility of the rules on reparation adopted in the framework of the ILC codification exercise.

Finally, Part 4 deals with the international law of sustainable development – an area which evolved most significantly in the past two decades. Laurence Boisson de Chazournes opens the Section with a contextualization of the case in light of the major developments that took place few years before the Judgment, in particular in 1992 during the Rio Conference on Environment and Development. Makane Moïse Mbengue then engages a ‘conversation’ with Judge Weeramantry (who has been rather critical on the caution that the Court exercised with respect to the legal status of sustainable development), showing that despite the judicial restraint that has characterized the treatment of the issue, the Judgment of the Court paved the way for a more progressive judicial construction of sustainable development. Leslie-Anne Duvic-Paoli’s analysis of the principles of vigilance and prevention highlights that while the ‘immaturity’ of this legal regime may explain the Court’s shying away from identifying precisely the content of the parties’ obligations, its stance notably on the principle of precaution was seminal as to the acknowledgment of its existence and significantly influenced later developments. Brian McGarry assesses the lexicon of ‘norms and standards’ that the Judgment uses to describe evolutions in international environmental law, and critiques these ambiguities by comparison to more recent case law at the Court and beyond.

Attila Tanzi’s conclusions reflect on the combination of the Court’s overall ‘preservative rationale’ with its ‘restorative-distributive justice’ approach to issues of reparation, while at the same time offering insightful comments on the preceding chapters.

Most contributors discussed the provisional results of their research in a joint seminar held in Ferrara in December 2017 marking the 20 years of the Gabčíkovo-Nagymaros Judgment; others have kindly accepted to step in at a later phase. We are grateful to all of them for participating in this endeavour and for their patience in the publication process. We also warmly thank Dr Ilaria Aquironi (University of Ferrara) for her valuable support with editing and proofreading, and Ms Khrystyna Gavrish (University of Ferrara) for preparing the bibliography.

Ferrara-Geneva-Leiden, October 2019