The government granted them entry as guest workers. "The first generation came at a time when the economy was booming, and they expected to make money and go back. That hasn't happened," said Jochen Hippler, a political science and Middle Eastern studies professor at Duisburg-Essen University. Clustered in neighborhood enclaves, such as Marxloh in Duisburg and Kreuzberg in Berlin, the children and grandchildren of that first immigrant wave grew up in Germany without ever attaining citizenship. Integration efforts began in earnest only recently, after the third generation of immigrants was born. Hampering those efforts is a distrust of Muslims heightened by the 9/11 attacks, an ethnic German population that abides foreigners warily, and an unwillingness among many in Turkish communities to break with their families and give up Turkish citizenship to become legally German. Until 2000, German law defined citizenship by ethnicity, rather than a person's place of birth.
