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). Consequently, a legal order can be defined as a system of right-duty (or claim-obligation) relations that regulate behaviour (action/inaction) among subjects in definite space and are procedurally organised in the vertical and horizontal sense according to time. An iconic representation of these minimum necessary concepts allows switching from natural language to a purely formal representation of the legal system(s) (deontic network). Within this 'geometrical' frame, general principles (the 'basis') of (international) law can be conceived of as general obligations, i.e. obligations erga omnes (towards everyone). Obligations erga omnes (ties), indivisible or divisible because of their content, link a subject (node) to every other subject of international law, endowed with a correlative claim (s - s), 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 breach.