Following extensive debate by the great theoreticians of public international law earlier in this century,1 it might seem that the completeness of the international legal order is now a banal issue, which should be remembered only as an academic dispute.2
It might have been so had the International Court of Justice not intervened, perhaps unintentionally, in its advisory opinion of 8 July 1996 concerning the Legality of the Threat or Use of Nuclear Weapons3 In her dissenting opinion, Judge Rosalyn Higgins argues that “the Court effectively pronounces a non liquet on the key issue on the grounds of uncertainty in the present state of law, and of facts”.4 In her view, the Court thus interrupted a line of case law which, in theory, had endorsed the idea of the completeness of international law and which, in practice, made it unthinkable that an international judge or arbitrator should actually pronounce a non liquet.5