Obligations erga omnes and the question of standing before the International Court of Justice

1. Introduction

As early as 1951, the International Court of Justice (ICJ, the Court) recognized that certain multilateral obligations in international law are such that the states bound by them ‘do not have any interests of their own; they merely have, one and all, a common interest’. ¹ The articulation of these common or collective interests may take the form of a multilateral treaty, ² which confers on states parties the right to invoke the responsibility of a breaching state. ³ Equally, a collective interest in compliance with certain obligations may be said to exist, whether under treaty law or customary international law, irrespective of their articulation as such. The growing recognition of this latter category of ‘obligations erga omnes’, ⁴ as they have been described by the ICJ, raises questions about the consequences of their inclusion in what remains in many respects an essentially bilateral international legal order. To begin with, it is necessary to determine ‘the precise identity of the omnes to whom the obligations are owed’, ⁵ including by distinguishing states’ interest in compliance with obligations erga omnes from their overarching interest in compliance with international law generally. ⁶ Having identified the recipients of the category of obligations erga omnes, the closely related question arises whether the breach by a state of such an obligation entitles a state to which the obligation is owed to invoke, individually, the responsibility of the breaching state, thereby ‘vindicat[ing] its interest as a member of the international community’. ⁷

The enforcement of obligations erga omnes requires a reappraisal of the means by which, and conditions under which, the responsibility of a breaching state might be invoked. Among the various routes available to a state seeking to invoke responsibility for a breach of international law are resort to countermeasures and the adjudication of the dispute. ⁸ In both cases, what is necessary is that the state seeking to invoke responsibility for the breach, as well as remedies, has ‘a specific right to do so’. ⁹ Such a right may derive, for example, from the terms of a multilateral treaty or from the fact that the state has been demonstrably injured by the breach. Broadly construed, standing or locus standi is thus ‘the requirement that...