?Full implementation of Article 73 of the UN Charter is an obligation for the administrative states as well for the UK for the territorial integrity of Mauritius. The Lancaster House Undertakings is under the ex injuria jus non oritur principle, that unjust acts cannot create law. The UK did not fulfill in good faith the obligations assumed by Article 73 in accordance with Article 2 (2) of the UN`s Charter. The Advisory Opinion interpreted by the ICJ is Article 38 (1) (b) created a new colony;the ICJ should have used Article 38 (1) (a) as the source of law for its decision.The decision of the ICJ is under the definition of an internationally wrongful act of an international organization by interpreting Article 38 (1) (b) of its Statute as the source for the Advisory Opinion interpretation.