anctions are foreseen by treaty provisions: of course they can only be specified and enforced by corresponding national rules.41 Such methods justify the theory of one of the greatest international lawyers of the century, the late professor George Scelle, on the "dédoublement fonctionnel."42 This means that, since there is no central executive power in international law, as a rule states have to ensure this function. However, whenever they act for the implementation of international legal rules, they do it on behalf and in the name of the international community as agents of the latter.
New international mechanisms for the surveillance of the implementation of treaty obligations by states are more and more numerous and more and more used. The term "international" may signify another application of the theory of the "dedoublement fonctionnel": a surveillance exercised by a state in the name of the international community. However, most often this means that an international body ensures this task.
Article 218 of the Law of the Sea Convention is a good illustration of the first method.43 According to it, when a vessel is voluntarily within a port or at an offshore terminal of a state, that state may undertake investigations, and, where the evidence so warrants, institute proceedings in respect of any discharge from the vessel outside the internal waters, territorial sea, or exclusive economic zone of that state in violation of applicable international rules and standards.44 Such surveillance thus covers acts that take place either on the high seas or in internal waters, territorial sea, or exclusive economic zone of another state, although in the latter case the port state cannot institute proceedings against the polluter, unless it is requested to do so by the concerned state.
Another method, which is gaining more and more importance, is the use of existing international bodies or the creation of new ones for the surveillance of the implementation of international legal obigations. Initially, such mechanisms were mainly created in the field of the international protection of human rights, with rather encouraging results. Different solutions are used: the international body may be an organ where states are represented, like the UN Commission on Human Rights,45 an expert group, like its Sub-Commission on the Prevention of Discrimination and Protection of Minorities,46 a quasi-judiciary organ like the European Commission of Human Rights,47 or a real tribunal, like the European or the American Court of Human Rights.48 The procedure depends not only on the nature of such bodies, but also on the progress of international awareness and cooperation in this field. Communications may be addressed in some cases by states,49 in others by individuals or groups of individuals,50 or even by both categories51 to determined bodies. Sometimes these are real applications submitted to strict rules of admissibility.52 The role of international public opinion is always very important, although the form of its intervention may be different according to the different procedures. Non-governmental organizations participate in the discussions of the UN Commission on Human Rights and are given the floor, but confidentiality is the rule in certain procedures.53 However, at the end, findings and reports on violations of human rights are generally made public and in some cases this constitutes the main sanction.54 In other circumstances the procedure ends with a formal decision of an international court of human rights that may condemn the concerned state to reparation.55
Such a complete outfit certainly does not exist for the surveillance of the implementation of obligations related to the environment, at least not yet. However, the "reporting system" is more and more often used. One of the models was Article 11 of the 1973 International Convention for the Prevention of Pollution from Ships (MARPOL),56 according to which the contracting parties undertake to communicate to the Intergovernmental Maritime Organization, inter alia, the text of laws, order