After Berlin, who's next?

What the Germans dreaded so much has finally happened: Berlin has been the target of an attack. The toll was high: 12 dead and 48 injured, some in very serious condition. As in Nice, a truck ploughed into the crowd, this time at a Christmas market. The presumed terrorist, arrested alive, is believed to be a refugee. The country is in shock. Angela Merkel's policies are under fire. After Paris, Brussels, Nice and now Berlin, can we still live safely in Europe? And what are the consequences for Switzerland?