The Benelux Economic Union treaty of 1944 was an early testing ground for the Europe of the Six, and it was the joint Benelux Memorandum, fathered by the far-sighted J. W. Beyen and presented in Messina in 1955, that gave the impetus to the creation of the common market. Indeed, it was the basis on which Belgian Foreign Minister Paul-Henri Spaak and his colleagues worked when setting the scene for the Treaty of Rome and the European Economic Community.
在过去几年中，比利时与荷兰的合作在欧洲发展中起到了至关重要的作用。1944年的荷比卢经济联盟条约曾作为欧洲六国早期的试验场，而且正是由远见卓识的约翰贝恩创始、并于1955年在墨西拿提出的《荷比卢联合备忘录》，为形成共同市场创造了动力。事实上，这也是比利时外长保罗-亨利·斯巴克及其同僚在为《罗马条约》和欧洲经济共同体创造条件时一直在努力维护的基础。