c) No derogation of
jus cogensWith the exception of the provision contained in Article 22, para.1 which emanates from the favor contractus principle, only peremptory norms of general international law (Latin:
jus cogens) can stand in the way of an agreement which has been freely entered into. Indeed, Article 53 of the
Vienna Convention specifies that a treaty conflicting with
jus cogens at the time of its conclusion is void. Similarly, a treaty becomes void and terminates, if it is in contradiction with a peremptory norm of international law which has newly emerged (
jus cogens superveniens - Article 64)
In that context we are in the presence of quite obscure provisions despite the definition of
jus cogens contained in Article 53: According to it, a peremptory norm of general international law is a norm accepted and recognized by the international community of States as a whole as a norm from which no derogation is permitted and which can be modified only by a subsequent norm of general international law having the same character.
As the
International Law Commission (ILC) nevertheless remarked itself in 1969 in its commentary on the draft articles for the international law of the treaties, there is no simple criterion which would allow to determine whether a rule belongs to j
us cogens.
This state of affairs has hardly evolved, although it seems that certain international norms for which criminals will have to stand before the International Criminal Court after having breached them constitute to a large extent the body of these sought
jus cogens rules. These penal provisions concern the prohibition of genocide, war crimes, crimes against humanity and the crime of aggression.
Eventually,
jus cogens seems to be a concept invented by international law experts who had been pursuing the aim of allowing natural law ideas to erupt into the legal regime of international treaties.
