Why are a United States of Europe, in theory and abstract the most rational option, practically impossible today? This book analyses the contradiction implied in having enormous world-level potential whilst lacking the force to execute this due to the current structural limitations of the European Union. It examines the principal historical background to the idea of a federal Europe and its successive achievements after the European Community was constituted. It also aims to show how a union has been shaped where supranational and intergovernmental impulses coexist in a contradictory way. The Great Recession of 2008 and the refugee crisis of 2015 have also posed ever more profound challenges to European integration. Eurosceptic and Europhobic forces that encourage nationalist withdrawal and opt for recipes of authoritarian populism are taking advantage of the errors and hesitancy of the community "establishment". After describing and interpreting the context and results of the crucial elections to the European Parliament in 2019, the programmes of the main parties in the six most populated states of the union are analysed. This takes the form of a questionnaire regarding the greater or lesser degree of integration advocated by each state, providing a highly representative picture of the great plurality of existing options. Lastly, it includes a chapter on the constitution of the Von der Leyen Commission, the finalisation of Brexit and the serious crisis the European Union has faced due to the Covid-19 pandemic.