In this dissertation, Máté Csernus explores the rules and principles applicable to international courts’ and tribunals’ subject matter jurisdiction over so-called incidental questions or implicated issues. The question of jurisdiction over such incidental questions constitutes a unique dilemma of subject matter jurisdiction, whereby the exercise of a court’s jurisdiction over a given issue depends on the resolution of a preliminary question that lies beyond the confines of that court’s jurisdiction. This complex challenge has existed in the practice of international courts for more than a century; however, it experienced an unexpected and significant resurgence in the 2010s, primarily due to its increased occurrence in law of the sea disputes before arbitral tribunals.
Given the absence of a treaty rule or a rule of customary international law governing the conditions and limits of the exercise of incidental jurisdiction, I rely on general principles as well as an analysis of the decisions of international courts and tribunals to identify the relevant applicable law. After reviewing a large body of inter-State decisions from a range of international courts and tribunals, Csernus conduct a detailed examination of six cases that are most pertinent to the question of incidental jurisdiction, scrutinizing not only the final decisions but also the parties’ arguments and, where relevant, dissenting opinions.
By delineating incidental jurisdiction from adjacent concepts relating to the application of external law -such as inherent and implied powers, or the application of external rules based on renvoi provisions - and by offering a detailed account of the modalities of its exercise, the dissertation identifies a narrow but distinct scope for the applicability of incidental jurisdiction.
The dissertation further argues that the varied subject matter contexts in which the incidental question problem may arise render it difficult to devise a single, unified test - comparable to the ‘very subject matter’ test in the context of indispensable third parties - to determine the permissibility and scope of incidental jurisdiction. Accordingly, Csernus adopts a more granular approach, identifying a broad range of relevant sub-questions and rules that may arise when a judicial forum encounters the incidental question problem. These include, inter alia, whether the incidental question problem should be conceptualized as an issue of jurisdiction, admissibility, or applicable law; the extent to which incidental questions arise in advisory proceedings; and whether incidental determinations have the force of res judicata.
Csernus defended his thesis on Oktober 16th at the University of Amsterdam. The thesis was supervised by prof. dr. Ingo Venzke and dr. Andrea Leiter.
Máté Csernus
Incidental Questions as a Jurisdictional Problem: The Limits of Subject Matter Jurisdiction in the Practice of International Courts and Tribunals