欧洲自己的经验告诉我们，关税联盟必须是发展自由贸易区的第一步，然后，关税联盟带来的更紧密的经济合作迟早会迫使其成员建立具有统一的内部市场一切特征的经济共同体。
Europe’s own experience has taught us that a customs union must be the first step, and that sooner or later the more intense economic cooperation that a customs union imposes will compel its members to establish an economic community that has all the characteristics of a unified internal market.