Les accords multilatéraux entre organisations, comme la convention-cadre de Madrid (1980), ne sont pas révélés très efficaces; ils n'ont permis, au mieux, que de mettre en place un cadre de coopération, auquel il faudrait donner un contenu concret au niveau national.
Agreements between multilateral organizations, such as the Madrid Outline Convention (1980), have not proved particularly effective, since they have chiefly served merely to establish cooperation guidelines which are intended to be fleshed out by means of national measures.