Contrary to the practical relevance of joint agreements for the implementation of the Union`s external relations, treaties have always been reluctant in this regard. The Treaty of Nice provided only for confusion in Article 133, paragraph 6, EC, while at least acknowledging its existence.19 The Lisbon Treaty, which rejected most of the special provisions within the framework of the Common Trade Policy, no longer mentions mixed agreements. Unlike Article 218 of the EU TFUE for (pure) EU agreements, there are also no contractual provisions governing the proper negotiation of such agreements20 Due to this lack of contractual basis (p.186) for mixing, the Court of Justice has been regularly asked to rule on disputes with joint agreements. On the contrary, as has already been said, it is quite common for the corresponding agreement to be concluded jointly between the Union and the Member States in the case of the optional mix. It has even been argued that the choice of mixture in this situation required a particular justification and was not merely optional.73 Mixedness would, according to this view, be contrary to Article 4, paragraph 3, of the EUSF, insofar as the Member States, by requesting their participation, make it difficult and cumbersome to achieve its objectives for the Union. A similar argument has been made with respect to Article 133, paragraph 5, EC (repealed by the Lisbon Treaty) in a case relating to the jurisdiction to rule on Vietnam`s accession to the WTO. While Article 133, paragraph 5, EC imposes a shared jurisdiction on certain issues under the otherwise exclusive common trade policy, it has been proposed that joint agreements should not be possible because of the problems they pose to ensure effective representation of the Union vis-à-vis its trading partners.74 (17) Since 1995, the European Commission`s Treaty Office database lists some 130 mentions for joint agreements. However, the constraints placed on Member States when they act within international organisations can be even more complex. Take the example of the International Organisation of Vine and Wine (OIV), which contributes, among other things, to the international harmonisation of the conditions of production and marketing of wine products and (S.200).
The decisions of the General Assembly are adopted by consensus. In order to prevent the adoption of resolutions, Member States must therefore express their disagreement, because mere tolerance will lead to their adoption. The resolutions adopted under the OIV are not binding. However, Regulation (EC) 479/2008 of the Council on the common organisation of the wine market114 contained dynamic references to these resolutions, so that the rules adopted under the OIV are also binding within the EU. In such a situation, the ERTA principle, now codified in Article 3, paragraph 2, of the TFUE, could force Member States to vote against the proposals and thus prevent the adoption of resolutions by the OIV General Assembly, unless they are based on a decision taken under Article 218, paragraph 9, of the EUTF. In such a situation, would the argument not be based, for whatever reason, on exclusivity, which is less likely in this area of comprehensive regulation of the Union than in a context such as that of PFOS, Article 4, paragraph 3, of the TREATY.115 In such a case, the argument would be that the inability of The Member States to prevent a resolution in the OIV would endanger the interests of the Union.