paragraph 152 in volume 2, chapter 9, Jurisdiction and Admissibility: General Concepts
The Court will not have jurisdiction over a duly constituted bilateral contentious case introduced by unilateral application if it appears that the principal issue to be decided, whatever the title of jurisdiction, requires the Court to pass on the legal position of a third State which is not a party to the proceedings. Several cases have raised this issue in different forms. The bilateralism of proceedin…