Showing ideas as causes: The origins of the European Union

Why did Western Europe create uniquely strong international institutions in the 1950s, setting the foundations for today's quasi-federal European Union? This article contests explanations of the European Economic Community (EEC) as a straightforward response to structural interdependence, or as an institutionally "path-dependent" variation on such a response. Only leadership based on certain ideas explains why Europeans created the EEC rather than pursuing cooperation within weaker institutions or standard diplomatic instruments. In France-the only major state that insisted on the "community" framework-divided preferences and issue-linkages created "multiple equilibria" that allowed leaders to mobilize support for several European strategies. The EEC strategy was selected over viable alternatives by leaders who stood out from their party, bureaucratic, sectoral, and regional allies in holding certain ideas about Europe. This demonstration of the major, distinct impact of ideas offers concrete support to the growing theoretical literature on ideas and norms.