81 Desuetude as a means of terminating a contract is not governed by the VCLT (Desuetudo). This means that the termination of a contract may be implied if it is the result of the parties` behaviour that they no longer consider the contract to be binding. 15 treaties may also extend their normative relevance beyond their actual parts and the extent of their activity by influencing the development of new rules of international customary law through state practice (including the practice of non-parties to a contract). Aid to the continental North Sea (Federal Republic of Germany/Denmark; Federal Republic of Germany/Netherlands) ( ICJ Rep 3), the ICJ explained the conditions under which such a trial could take place. The ICJ first indicated that the provision in question should be prescriptive, as it can be considered the basis of a general rule of law; and second, that widespread and representative participation in the convention alone could suffice, provided that it includes, even without a long period of time, states whose interests have been particularly affected. The ICJ also explained the relationship between customary international law and treaty law in the case of Nicaragua (Nicaragua/United States of America) (hereinafter the case of Nicaragua) of 1986, in which it focused in particular on the parallel existence of contractual rules and rules of international customary law, with identical or similar obligations. In such cases, according to the ICJ, the treaty continues to function as between the contracting parties, while parallel relations between non-parties or between non-parties and parties are governed by corresponding customary international law. Twenty-nine states can apply any procedure they choose to reach a legally binding agreement between them. However, in the absence of any other agreement, the procedures set out in the LTCV apply; these procedures reflect the practice that had developed between states prior to the codification of the law in the VCLT.
12 The VCLT was the result of the work of the ILC and the United Nations Conference on Treaty Law of 1968 and 1969. It came into force on January 27, 1980. The VCLT has generally addressed customary international law in its material provisions, although at the time of its entry into force, some doubts about the customary status of international law in some of its provisions, such as Articles 34-38 (treaties and third countries) and 65-68 (procedures for alleged nullity or suspension of contracts) have raised doubts, which are probably still not customary international law.