|From the analytical viewpoint a norm can formally be regarded as a right-duty (or
claim-obligation) relation (1) that regulates behaviour (action/inaction) (2) among
subjects (3) in definite space (4) and time (5). In normative terms, general principles
(the ‘basis’) of (international) law can be conceived of as general obligations, i.e.
obligations erga omnes (towards everyone). Obligations erga omnes, indivisible or
divisible because of their content, link a subject to every other subject of international
law, endowed with a correlative claim, so that the whole obligations erga omnes are
matched by the whole claims erga omnes of all the subjects of international law.
Indivisible obligations erga omnes are unavailable from the viewpoint of the power, so
cogentes, breaches violate necessarily all the correlative claims, possibly enabling every
subject to invoke the responsibility and impose sanctions. Correspondingly, sanctions
should be regarded as indivisible obligations erga omnes, the violation of which allows
universal enforcement. Nevertheless, specifically by reason of the gravity of the breach,
it is possible to split primary and secondary norms, conceiving of the sanction as a
bilateral relation allowing solely reciprocal enforcement in the case of an infringement.
Divisible obligations erga omnes are available from the viewpoint of the power, so
dispositivae, breaches must be seen as relative, enabling only the subject(s) injured to
invoke the responsibility and impose sanctions. Correspondingly, sanctions should be
regarded as bilateral obligations, the infringement of which gives rise to reciprocal
enforcement. Nevertheless, it is possible to figure out that specifically the gravity of the
breach ‘unifies’ the primary divisible obligation, allowing universal invocation of the
responsibility, so that the secondary obligation could be either bilateral or a general
indivisible one, respectively permitting relative or absolute enforcement in the case of a