Nullité absolue des traités et inapplication de la Convention de Vienne

This contribution investigates the reasons for the inapplication of the rules on the absolute nullity of treaties contained in the 1969 Vienna Convention on the Law of Treaties. The argument put forward is that the codification of absolute nullity in treaty law was both a necessary and fanciful choice at the time. Necessary because there was already a jurisprudential practice that had declared some treaties concluded in violation of rules that would later be qualified as "ius cogens" null and void. And also because, after the end of the Second World War, the idea spread that international law should privilege a "strong" legality over the effectiveness of legal situations. It was unrealistic because of the difficulty of transferring the typical characteristics of the absolute nullity of domestic law into the international legal system.