This book presents complementary studies of differences in public opinion regarding European integration processes. The May 2004 enlargement brought ten new member countries into the European Union and the macro-geography of identities and associated articulations of public opinion, across the twenty-five polities, changed significantly. The author uses the statistical tools of principal component analysis and standardised multivariate regression analysis (LISREL modelling) to examene differences in public opinion among the twenty-five polities of the enlarged European Union. The analyses of public opinion are based upon postulated explanatory models concerning, in particular, processes of integration, including the deepening, enlargement and two-speed institutional development of the European Union. The book provides a comprehensive reflection concerning public opinion differences that will shape the European Union for years to come.