2026 ESIL Monograph Prize Winner

The 2026 ESIL Monograph Prize was awarded in September 2026 during the 21st ESIL Annual Conference in Málaga to Nikolaos Voulgaris for his work The ICJ and Multi-forum Litigation Strategy (Brill│Nijhoff, 2025).

Jury’s decision:

Nikolaos Voulgaris’ book “The ICJ and Multi-forum Litigation Strategy” is an original and timely contribution to contemporary international legal scholarship. The book examines the increasing use by States of multiple international judicial fora as part of broader litigation strategies, placing the International Court of Justice at the center of a significant transformation in international dispute settlement.

The author identifies and develops in an interdisciplinary way an under-explored field of research and, moving beyond existing legal analyses, he demonstrates the specific features of multi-forum litigation involving States. The concept of “multi-forum litigation strategy” provides a clear and valuable analytical framework, avoiding the limitations of broader concepts such as “lawfare” or “strategic litigation”.

A distinctive merit of the work is its clear strategic perspective. The book demonstrates that States may resort to international courts not only to obtain judicial remedies, but also to pursue wider diplomatic and political objectives. At the same time, it carefully examines how such strategic uses interact with the judicial nature and legitimacy of international courts. This approach offers important insights into the evolving role of the ICJ as both a dispute-settlement institution and an influential actor in international affairs.

The book is remarkably well-organized. It proceeds from the conceptual definition of multi-forum litigation strategy to a detailed analysis of the different forms of ICJ engagement, including contentious proceedings, provisional measures, and advisory opinions. The clear structure allows the author to address complex questions concerning jurisdiction, procedure, State strategy, and institutional authority in a coherent and accessible manner.

The interdisciplinary dimension of the research is also particularly significant. Voulgaris combines rigorous legal analysis with insights from international relations, showing that contemporary international litigation cannot be understood through legal doctrine alone. This broader perspective enriches the understanding of judicial institutions as operating within a complex strategic environment.

The book demonstrates an impressive command of international jurisprudence. It relies on extensive and accurate analysis of ICJ case-law and related proceedings before other international bodies, examining contemporary disputes involving Ukraine and Russia, Qatar and United Arab Emirates, Mauritius and the United Kingdom, Armenia and Azerbaijan, South Africa and Israel, The Gambia and Myanmar. Judicial decisions are analytically used to support broader conclusions on the limits and possibilities of international adjudication.

A further important merit of the book is that it highlights the implications of multi-forum litigation for the authority and jurisdiction of the ICJ. By examining how States engage, test, and sometimes strategically frame the Court’s jurisdiction, the work contributes to a deeper understanding of the Court’s future role, its capacity to respond to complex disputes, and its continuing authority within the international legal order.

Overall, The ICJ and Multi-forum Litigation Strategy combines originality, strategic insight, interdisciplinary depth, and outstanding case-law research. It represents a major contribution to international dispute settlement scholarship and accordingly it is granted the European Society of International Law Book Prize.