his is not the place to discuss the legal nature of such resolutions and especially their binding force. At a minimum it can be asserted that they participate in the creation of new international law rules, formulating for the first time emerging social values that later on may be formally confirmed by international conventions. This was the way international law was developed in new fields such as the international protection of human rights, or the status of outer space. For environmental protection, the evolution is less lineal, but texts such as the 1972 Stockholm Declaration11 or the World Charter for Nature, adopted and solemnly proclaimed by the UN General Assembly on 28 October 1982,12 certainly have paved the way for formal legislative activities.
Soft-law instruments can also play a more technical role. "Resolutions," "conclusions," and "guidelines," may include technical details that are to be evaluated by states and may be included, at the end of the day, either in a formal international treaty13 or introduced in national legislation.14 This can be explained by the newness of the solutions suggested by the international bodies - understanding that such newness is mostly imposed by a new situation that has to be coped with.
Soft-law rules can also be included in formally binding international instruments, i.e. treaty provisions. As a matter of fact, quite often such provisions contain nothing more than strong recommendations for the contracting parties. Without speaking of clauses such as "each State Party to this convention shall endeavor, in so far as possible, and as appropriate for each country..."15 which can hardly be con sidered as imposing strict obligations upon states, the content of the treaty itself may be, in reality, nothing more than a declaration of intention. A good example for this is the 1979 Convention on Long-Range Transboundary Air Pollution.16 The contracting parties "are determined to protect man and his environment against air pollution and shall endeavor to limit and, as far as possible, gradually reduce and prevent air pollution...."17 They also will "develop without undue delay, policies and strategies which shall serve as a means of combating the discharge of air pollutants.''18
They also shall undertake "to develop the best policies and strategies" in order to combat air pollution.19 As a matter of fact, in spite of its appearances, this convention is an operative one and has created a useful framework for everyday cooperation as well as for the development of further international rules that are more stringent.20
A growing number of treaties do not include immediate obligations for the contracting states, instead they develop programmes of action. One of the first was the Paris Convention for the Prevention of Marine Pollution from Land-Based Sources, adopted on 4 June 1974, which provides that, for carrying out the undertakings resulting from that Convention, "the Contracting Parties, jointly or individually as appropriate, shall implement programmes and measures.. "21 It may be considered that such provisions are between "soft" and "hard" treaty obligations, since the content of the duties resulting from the treaty are not defined. As a result, it could hardly be enforced by an international jurisdiction.
Not very different from this method is that of the "pactum contrahendi," i.e. the conclusion of a treaty that mainly provides for cooperation between the contracting parties, hoping that this may result in the adoption of more precise obligations. One of the earliest models in this field was the Convention on the Conservation of Migratory Species of Wild Animals, adopted in Bonn on 23 June 1979, according to which the parties shall endeavour to abide by agreements covering the conservation and management of certain migratory species.22 The most important application of this method, so far, seems to be the 1985 Vienna Convention for the Protection of the Ozone Layer, according to which the parties shall in accordance with the means at their disposal and their capabilities:23 "C