As the twenty-first century opened and ongoing globalization transformed European society and politics, Europeans witnessed the remaking of their ethnic communities. First, Europe experienced a remarkable decline in birthrates that seemed to predict a shrinking and aging population in the future. Second, the peaceful, wealthy European Union attracted rapidly growing numbers of refugees and immigrants from the former Soviet Union and East Bloc, North Africa, and the Middle East. The unexpected arrival of so many newcomers raised perplexing questions about ethnic diversity and the costs and benefits of multiculturalism.