The natural growing of population could been stopped in most industrial states till today. Indeed nearly each industrial state has got a low growing of population - the Federal Republic of Germany too -, but thaat´s only caused by immigrants.
The pression of immigration will become much higher in future and will prevent the necessary reduction of the overpopulation also in the industrial states. A lot of people in the industrial fee themselves to threatend by the rising number of foreigners. At the otherside there are people who stand for immigration in order to compensate the waste of native people.
Experiences of the past verify that the integration of immigrant can be successfull indeed. So a lot of French Hugenotts immigrated from France to Prussia - 20 % of the inhabitants of Berlin were Frenchmen in former days. Well known is the mass imigration from Poland to the Ruhr - district about 100 years ago, during nearly only high qualificated specialists came from Ireland. The integration of this people into our society of today. It´s sure you cannot transmit this matter to oresent time, because the immigrants were really need by the new prosperung German Reich, as well as specialist and the mass of simple workers.
But times have changed. Foreign citizens still don´t only make "simple and dirty works" native people do not want to do at all. When I got my examen of junior high school in 1975 there was really no foreigner in my age - group. But today there are turkish lwayers, doctors, scientist etc.. A lot of Germans regard them to be an unwelcome rivalry...
Immigration and emmigration are no solution to solve intern ethnic and national problems principially. But both is senseful and useful, because an international exchange of people, cultures and ideas can answer a purpose for everybody. But we will do nobody a favour to allow his immigration in our country, during we are not able so sure his basic of existence. Controlls and laws for immigration are necessary like they are normal in the classic immigration countries like the USA, Canada and Australia for decades.
But at first we ´ve to think about what we want at all. Shall the descendants of today´s Turkish people ne Turks or Germans? ...or may be it will be the same to be a German or a Turk? It seems to be that the state of Turkey is not really happy about the emigration of Turkish people, because Turkey fears that the emigrants will get lost for the Turkishdom. It would be necessary to find a consence.
But it would be inhuman to look upon Turks and other immigrants as a compensation for our own declining German population. Our state already improves its own incapacity more tha enough.