Customary International Law

1. Customary International Law • ‘…international custom, as evidence of a general practice accepted as law’ • equally influential to treaty law but considerably more complicated in its application • 2 elements: 1. consistent and general international practice; 2. accepted as law by the international community

2. opinio juris • acting as though legally bound • rarely explicit • acceptance, acquiescence, protest and denial • municipal courts (consider what evidence may be provided by SCC decision in Suresh) • publicists

3. Mustering the Evidence • state practice: unilateral action • distinguished from convention and convenience and contract • long practice not necessary, but helpful • municipal courts • treaty patterns (multiple treaties, big treaties) • general relationship btw treaty and customary international law

4. Exceptions, Objections and local norms • customary law may exist without being applicable throughout the international system; eg Portugal v India • those who object persistently are unlikely to be bound; Columbia v Peru • those who begin objecting later may well be bound

5. North Sea Continental Shelf Cases • rigourous standards applied to question of opinio juris • to what extent did the recently agreed to Convention on the Continental Shelf express a rule of customary intl law? • argued that drafting process clarified custom • majority: reservations; ratifications; ‘special circumstances’; time; non-party actions since C • how is the case resolved?

7. jus cogens • special sub-category of international custom • peremptory, cannot be contradicted • no clearly enumerated list…candidates? • VCLT: treaties will be invalid if contradict • Suresh – 3 types of evidence: prohibited in many treaties; no state has legalized it and they deny involvement; ‘publicists’

8. jus cogens : food for thought • What did the Supreme Court of Canada decide in Suresh? • What did the Ontario Court of Appeal decide in Bouzari?