Migration's impact on German society has been dramatic. Indeed, key political events in modern German history cannot be fully understood without reference to migration's influence. Domestic and international affairs were greatly affected by the millions of ethnic Germans who were either expelled from the homelands or arrived as refugees during and after the Second World War. The construction (and later the fall) of the Berlin Wall would not have occurred without the massive emigration of refugees from the German Democratic Republic. And without the Wall, there would have been less reason...