Many European and American observers of the EC have criticized "intergovemmentalist" ac counts for exaggerating the extent of member state control over the process of European integra tion. This essay seeks to ground these criticisms in a "historical institutionalist" account that stresses the need to study European integration as a political process which unfolds over time. Such a perspective highlights the limits of member-state control over long-term institutional de velopment, due to preoccupation with shorHerm concerns, the ubiquity of unintended conse quences, and processes that "lock in" past decusions and make reassertions of member-state control difficult. Brief examination of the evolution of social policy in the EC suggests the limita tions of treating the EC as an international regime facilitating collective action among essentially sovereign states. It is ore useful to view integration as a "path-dependent" process that has pro duced a fragmented but still discernible "multitiered" European polity.