By Jean Pisani-Ferry
The first six months of 2007 have been momentous ones for the European Union. In January, the accession of Bulgaria and Romania completed its eastern enlargement. In March, it set itself ambitious targets for a common energy and climate change strategy. And in June it reached agreement on a new draft treaty. José Manuel Barroso, European Commission president, and Angela Merkel, the German chancellor whose country then held the rotating presidency of the European Council, deserve their holidays: there could have been worse ways to mark the 50th anniversary of the Treaty of Rome.