The International Judicial Function and How We Think About It: Non Liquet, Revisited

Abstract A non liquet occurs when a competent international court declares itself unable to address substantive issues of international law due to a gap ( lacuna ) in the applicable law. While the possibility of non liquet was widely accepted among 19th-century scholars, it became increasingly controversial as international law evolved into a more structured legal system. In the 1950s and 1960s, amidst a re-negotiation of international rules in various fields driven by the emergence of geopolitical rivalry, new States and technological progress, the concept featured in the writings of prominent scholars such as Hersch Lauterpacht, Julius Stone, Hans Kelsen, and Rosalyn Higgins, mainly reflecting their conception about the international judicial function. Since then, however, the admissibility of non liquet has remained a marginal and underexplored aspect of procedural law. This is also because the limited number of precedents has contributed to the prevailing view that international courts are subject to a general prohibition against declaring a non liquet . This article re-examines the problem of non liquet with the aim of bringing it back into the spotlight – not merely from a theoretical perspective, but as a practical concern. It argues that, far from being prohibited, non liquet , in both its formal and material dimensions, remains a procedurally and normatively admissible technique of last resort, and that the International Court of Justice has, in fact, resorted to it when confronted with real gaps in the law. More significantly, in an era marked by geopolitical fragmentation and the inability or unwillingness of political actors to regulate adequately pressing global issues, the power of international courts to acknowledge legal indeterminacy through non liquets may offer important advantages over other alternatives.