The dreaded avian flu has crossed the borders of the European Union. Greek officials said this week that turkeys on a Greek island had succumbed to avian flu, probably caught from birds on a nearby Turkish island. Turkey and Romania, which are not E.U. members, both confirmed cases last week. European Commission President Jose Manuel Barroso said that the E.U. should be prepared to take drastic measuresincluding mass slaughter of poultryto prevent further spread. The impact on European agriculture could be enormous. In 2003, an avian flu outbreak in the Netherlands led to the slaughter of 30 million birds.