Customary international law | bilateral versus multilateral customary international law

Bilateral versus multilateral customary international law

The recognition of different customary laws can range from simple bilateral recognition of customary laws to worldwide multilateral recognition. Regional customs can become customary international law in their respective regions, but do not become customary international law for nations outside the region. The existence of bilateral customary law was recognized by the International Court of Justice in the Right of Passage Over Indian Territory case between Portugal and India, in which the court found "no reason why long continued practice between the two states accepted by them as regulating their relations should not form the basis of mutual rights and obligations between the two states".[18]