File - This Aug. 31, 1990, file photo shows the last page of the German unification treaty as it was signed in East Berlin, Germany. It bears the signatures of West German Interior Minister Wolfgang Schaeuble and of East German chief negotiator Guenther Krause plus the seals of West and East Germany. Germany marks a quarter-century as a reunited nation on Saturday, Oct. 3, 2015, with two leaders from the formerly communist east heading a country that increasingly asserts itself as Europe’s political heavyweight, and now faces a new challenge in a refugee influx that will demand deep reserves of resourcefulness and patience. (AP Photo/Rainer Klostermeier, File)