On 9 May 1950 the foreign minister of France, Robert Schuman, proposed that “the entire Franco-German production of coal and steel be placed under a common High Authority in an organization open to the other countries of Europe.” By pooling their heavy industry interests, he proceeded, the two powerful antagonists could end the competition that had caused armed conflict twice in the previous half-century and create the essential conditions for a new era of material growth and prosperity. On 18 April 1951, after nearly a year of negotiations, the representatives of France, West Germany, Italy, and the Benelux nations concluded the Treaty of Paris instituting the European Coal and Steel Community (ECSC), and on 10 August of the following year it began operations in Luxemburg.

Europe's “first great experiment in supranationalism” triggered an immense outpouring of scholarship. Inspired by the hope that a “new form of economic and political cooperation” had been invented, a number of leading social scientists set about meticulous and searching examination of the Schuman Plan and the ECSC, producing an impressive literature. Its overall conclusions were sadly disappointing, however. William Diebold reluctantly ended his masterful and immensely useful Schuman Plan: A Study in Economic Cooperation without having proven that the organization had had a measurable economic impact. Ernst Haas, whose Uniting of Europe presents the most thoroughly documented of the many cases argued for what might be called a dialectic of integration, felt obliged to introduce the 1968 reissue of his book with a thirty-seven-page apology for the failure of the “spillover effect” to work as predicted in the initial edition.