The case-law of the International Court of Justice (Court) is replete with arguments about whether the Court has jurisdiction to entertain the particular dispute (or request for advisory opinion) with which the Court is faced. These arguments are framed at one level as matters of interpretation of the relevant instruments. But they typically play out as well a multiplicity of variations on the overlapping themes of sovereignty (the extent to which states have been prepared to concede decision-making to third-party settlement mechanisms) and justiciability (the extent to which they will accept that an issue may be governed by ‘law’ and thus be susceptible to resolution by judicial actors).