Shared Responsibility in the International Court of Justice

In recent years, the International Court of Justice has been increasingly asked to adjudicate upon claims of State responsibility that raise or at least touch upon the possibility of international responsibility of multiple entities. In different substantive contexts, these cases raise the same conceptual question about responsibility incurred not only by the particular respondent State but also by other entities, whether States, international organisations or non-recognised States. Such concerns might be articulated by reference to the concept of ‘shared responsibility’, that for the present purposes will be taken to refer to responsibility incurred (1) by multiple actors (2) for contribution to a single outcome, (3) with the responsibility distributed separately. The focus of this article is on procedural matters, and in particular on how shared responsibility may be implemented in the ICJ. The argument will be made in three steps, dealing in turn with the manner in which cases concerning shared responsibility could be brought before the Court, the way how such cases could be handled, and the challenges raised in such cases by absent parties.