Indispensable Party
The indispensable party rule is a procedural condition for the exercise of contentious jurisdiction by international courts and tribunals, and therefore it represents a limit of the judicial function. Its main purpose is to strike a balance between the interests of the parties to a dispute and the interests of third parties absent from the proceedings. The discretion that is implicit in the indispensable party notion explains the flexibility with which international courts and tribunals have applied it. It may also explain different degrees of reliance when one compares contentious cases and advisory proceedings precisely because of the factors just mentioned: a reduced role for consent, broader participation of third parties, and, generally, an institutional mission that justifies the exercise of the advisory judicial function, which may appear better equipped to deal with multilateral disputes.