International Legal Hierarchy Revisited: The Status of Obligations Erga Omnes

Increasingly, international legal arguments exploit the peculiar nature of obligations erga omnes. This practice raises questions about the precise legal status of norms expressing such obligations relative to other norms of international law. According to an oft-made suggestion, whether a norm is part of the international jus cogens or not, when it expresses obligations erga omnes it is hierarchically superior to all other norms of non-peremptory international law. This essay inquires into the justification of this theory – throughout the essay referred to as “the Theory on the Superior Status of Erga Omnes Obligations”. As shown in section 2, irrespective of whether inferential legal evidence exists or not, the Theory on the Superior Status of Obligations Erga Omnes can be explained by reference to the non-reciprocal character of such obligations. However, logic requires that the theory be restated to include also interdependent obligations and obligations erga omnes partes. As shown in section 3, although inferential legal evidence provides some support for the Theory on the Superior Status of Obligations Erga Omnes, the evidence is not entirely consistent. As shown in section 4, if the theory on the superior status of obligations erga omnes is adopted and applied on a wide scale, this will have detrimental effects on the overall understanding of international law. Rather than a more properly functioning international legal system, confusion and disorganization will ensue.