How did you come to choose your research topic — the practice of justification of the International Court of Justice?

When I first started thinking about my thesis topic, I knew I was interested in international adjudication and legal argumentation, but I needed to work to identify the precise aspect I wanted to explore. Conversations with colleagues and professors helped me narrow down my interest to how international courts and tribunals justify their decisions. The International Court of Justice seemed like a natural choice as a main focus of my investigation. It is the principal judicial organ of the United Nations, deals with a wide variety of cases, and offers an ideal context to study how reasons and justification function in different areas of law. At the beginning, I thought I would simply look at the reasons explicitly given in judgments and try to classify them according to Article 38 of the Court’s Statute. However, as I read and re-read the Court’s decisions, I realised that justification is much broader and more complex. It is not only about the reasons written in the text, but also about how the Court structures its decisions, frames its arguments, and communicates with multiple audiences. Over time, this understanding shaped my topic into a study of the Court’s broader practice of justification, which became the focus of my thesis.

Can you describe your thesis questions and the methodology you use to approach those questions?

The evolution of my research led me to frame a main question: “How does the International Court of Justice justify its judgments and advisory opinions?” This question encompasses both a descriptive dimension, exploring how justification actually takes place, and an explanatory dimension, seeking to understand why it manifests in specific ways. For this explanatory dimension, I started from the assumption that the presence or absence of certain parameters could explain why justification might vary depending on the concrete circumstances of each case. To operationalise this inquiry, I developed three interconnected sub-questions: How does the audience influence the choice of the International Court of Justice’s justificatory practice? How is the justificatory practice shaped by the type of act the International Court of Justice has to issue or render? And how does the issue the Court has to deal with impact its justificatory practice?

My methodological approach was fundamentally inductive, growing out of countless hours spent in repeated, close reading of (all) International Court of Justice judgments and advisory opinions. Rather than working with a sample, I made the deliberate choice to analyse the complete body of International Court of Justice decisions. This comprehensive approach was essential, I believe, because, the more I read, the more I realised that sampling might capture accidental tendencies rather than the structural patterns I was searching for. From this immersive reading process, I developed a taxonomy for analysing the Court’s practice. While this framework was shaped by New Rhetoric, particularly Perelman’s insight that discourse is always addressed to an audience, much of it emerged directly from observation. I identified recurring categories of reasons that the Court employs, among others: the mirror game, where the Court follows the parties’ arguments; quasi-logical reconstruction; framing devices that prepare the Court’s argumentation; the dynamics of making visible and making invisible; references to the judicial function; engagement with external elements; the use of precedents; and obiter dicta, which, despite common assumptions, can serve important justificatory purposes. I then correlated these coded categories with three key parameters: audience, type of act, and issue. This correlation allowed me to understand how the Court’s justificatory strategies might shift depending on these different factors, over time but also within single cases.

I have also recognised that textual analysis alone could not reveal everything. To understand the internal dynamics of how justification actually develops, I conducted interviews with individuals that have worked at the ICJ, complemented by an official interview with the Information Department of the Court. These conversations explored drafting and deliberation processes, aesthetic choices and their interpretation, and the communicative dimension of the Court’s work.

What are your major findings?

My thesis shows that the ICJ’s practice of justification is far more complex than simply applying Article 38 of the ICJ’s Statute to the facts. By using the methodology I just mentioned (comprehensive analysis of all judgments and advisory opinions, complemented by interviews with former ICJ staff), the thesis identifies several key findings. One of its main theoretical contributions is the development of the concept of practice of justification, understood as a process composed of three interrelated phases: rationalising, structuring, and sharing. These stages illustrate how the Court formulates, organises, and communicates its reasons through both textual and extratextual means. The study shows that justifications emerge not only in the reasons themselves but also through style, structure, and institutional communication. The reasons chosen reflect not only logic but, for instance, also the need to maintain institutional coherence and consensus among judges. At the same time, justifications serve instrumental purposes beyond explanation: they help the Court signal consistency, assert authority, engage with different audiences, and adapt to its institutional context. Ultimately, the thesis reveals justification as a multi-layered and evolving practice that not only shapes how the Court explains and presents its decisions, but also serves as a lens through which we can better understand the Court’s role, its institutional identity, and the way it perceives itself.

What are you doing now?

I am currently working as a Lecturer in International and European Law at the Department of Public Law and Governance, Tilburg University, where I am pleased to continue growing as an academic.

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On 18 September 2025, Irene Miano defended with summa cum laude her PhD thesis in International law, titled “‘For These Reasons’: The Practice of Justification of the International Court of Justice”. Professor Fuad Zarbiyev presided over the committee, which included Professor Andrea Bianchi, thesis director, and Professor Moshe Hirsch, Faculty of Law, The Hebrew University of Jerusalem, Israel.

Citation of the PhD thesis: 
Miano, Irene. “‘For These Reasons’: The Practice of Justification of the International Court of Justice.” PhD thesis, Graduate Institute of International and Development Studies, Geneva, 2025.
Access:
An abstract of the PhD thesis is available on this page of the Geneva Graduate Institute’s repository. As the thesis itself is embargoed until October 2028, please contact Dr Miano for access.

Banner image: FrankHH / Shutterstock.
Interview by Nathalie Tanner, Research Office.