The Royal University Institute of European Studies carried out a research project financed by the European Commission under the title "Unity and flexibility in the future of the European Union. The challenge of Reinforced Cooperation" during 2008 and 2009. 

The purpose of this project was to study the instrument of enhanced cooperation after the entry into force of the Treaty of Lisbon, with the aim of analyzing the potential of the new system in a series of areas where the development of this mechanism can be considered in the medium or long term. Thus, after examining the evolution of the enhanced cooperation clauses in the successive Treaties and detailing the specific innovations of Lisbon, this project studied the possible development of enhanced cooperation in the areas of energy, foreign, security and defence policy, as well as, from a broader perspective, enhanced cooperation and formulas for differentiated integration in the areas of economic governance, social policy and the area of freedom, security and justice.



Within the framework of this project, the seminar "Unity and flexibility in the future of the European Union, the challenge of enhanced cooperation" was organized at the San Pablo CEU University on April 29, 2009.



As a culmination to this project, a book was published in 2010, "Unity and Flexibility in the Future of the European Union". The Challenge of Enhanced Cooperation, in which, over the course of six chapters, the main ideas and conclusions that emerged during the project are set out.