Prof. Pierre-Henri Imbert gives two examples that highlight this fundamental difference, by comparing article 39 of the revised General Act of Arbitration of 28 April 1949 with article 27 of the European Convention of 29 April 1957 for the peaceful settlement of disputes (Les réserves aux traités multilatéraux, Pedone, Paris, 1979, p. 10); under article 39, paragraph 2, of the General Act, reservations that are exhaustively enumerated and “must be indicated at the time of accession … may be such as to exclude from the procedure described in the present act: (a) Disputes arising out of facts prior to the accession either of the Party making the reservation or of any other Party with whom the said Party may have a dispute; (b) Disputes concerning questions which by international law are solely within the domestic jurisdiction of States”.
Le professeur Pierre-Henri Imbert donne deux exemples qui font bien ressortir cette différence essentielle en opposant l'article 39 de l'Acte général d'arbitrage révisé du 28 avril 1949 à l'article 27 de la Convention européenne du 29 avril 1957 sur le règlement pacifique des différends (Les réserves aux traités multilatéraux, Paris, Pedone, 1979, p.