1. Declaration of optional clause can only relate to disputes between states, Nauru acceded to independence in 1968, and then become a State, since that time no agreement to settle disputes regarding the rehabilitation has been show to exist.
6. The mandate system was created in the interest of the inhabitants of the territory, and of humanity in general, as an institution with an international object. The Trust had to be exercised for the benefit of the peoples concerned, who were admitted to have interest in their own.
Australia raised the question whether the liability of the three states would be ‘join & several’ (solidaire) so that any one of the three would be liable to make full reparation. The answer is reserved to the merits, but it is independent of the question whether Australia can be sued alone. There is not reason why a claim brought against only one of the three states should be declared inadmissible. Because the claim raises questions of the administration which was shared with two other states, it cannot be denied that Australia had obligations under the Trusteeship, it its capacity as one of the three states forming the administration.
(55) In the present case the determination of responsibility of NZ or UK is not a prerequisite for the determination of the responsibility of Australia, the only object of Nauru’s claims…In the present case a finding by the court regarding the existence or the content of state responsibility attributed to Australia by Nauru might well have implication for the legal situation of the two other states concerned, but no finding in respect of that legal situation will be needed as a basis fore the court’s decision on Nauru’s claims against Australia.
It is true that jurisdiction depends on the consent of states, but in the present case the interest of NZ & UK do not constitute the very subject matter of the judgement, a 3rd state that could be affected by the decision can asked to intervene art 62 and its interest is safeguard by relativity of sentence art 59