A treaty is void ab initio (from the beginning), if at the time of its conclusion it conflicts with a peremptory norm of general international law, i.e., jus cogens (Art. 53). “If a new peremptory norm of general international law emerges, any
existing treaty which is in conflict with that norm becomes void and terminates” (Art. 64). Thus, a treaty is void if it is in contradiction with the existing or new jus cogens.