Reviewing the difficulties of codification: on Ago's classification of obligations of means and obligations of result in relation to state responsibility

As Special Rapporteur to the International Law Commission, Roberto Ago enlarged the vision of the scope of state responsibility including new legal relations between the wrongdoer and the victim or third parties. He also eliminated any reference to damage in the definition of state responsibility. Finally, he proposed new classifications of wrongdoings and obligations. However, this latter makes use of a misleading terminology to designate inappropriate distinctions which do not necessarily correspond to any specific differentiation of legal regime in Part Two of the ILC's Draft Articles on State Responsibility. This is particularly the case for the classification of obligations of means and obligations of result. It is thus necessary to reassess the legal bearing of this distinction in terms of its civil law origin in order to decide whether it would be worthwhile to incorporate it, even indirectly, in the final version of the ILC's project. This is also the case for the overly sophisticated relationship established by Ago between some categories of obligations and wrongful acts. This paper argues that an opportunity now exists to make these distinctions more reliable and effective, even at the price of eliminating some of them.