Dr Grabbe is deputy director of the Centre for European Reform (CER) which is a think tank devoted to improving the quality of the debate on the future of European Union. Eastward enlargement is the European Union`s greatest contribution to security and stability in the 21st century. The benefits are huge but the integration of 10 new members will also put a strain on the Union`s institutions and change the way in which they currently function while transforming the face of the European Union in the process. Dr. Grabbe`s book “`The constellations of Europe: How Enlargement will Transform the European Union”` will be published later this year by CER