The obstacles facing the Special Rapporteur of the International Law Commission in drawing up a draft on the “content, forms and degrees of international responsibility” arise mainly out of the absence in the first part of the draft of any real theory of international delict introducing into this general concept criteria for differentiation which would enable more restricted categories to be distinguished. Once it is admitted that responsibility (defined in the abstract as the emergence of new legal relations between the wrongdoer on the one hand, and his victim or third parties on the other) can take a variety of forms, covers a broad spectrum and involves different subjects according to the legal causes which gave rise to it, then we can no longer avoid analyzing those causes. The internationally wrongful act, defined as the violation by a State of an international obligation, ceases to be the homogeneous legal concept of the first part of the draft adopted on first reading by the International Law Commission, but instead breaks down into a multiplicity of acts.