German reunification (Wiedervereinigung) refers to the reunification of East Germany and West Germany under a single government. An agreement to reunite both parts of Germany was reached on February 13, 1990. This agreement was implemented through the so-called "Two Plus Four Treaty", signed on September 12, 1990 by the four occupying powers: the United States, United Kingdom, the Soviet Union, and France, as well as by the Federal Republic of Germany (West Germany) and the German Democratic Republic (East Germany). The reunified Germany remained a member of the European Community (later European Union) and the NATO.
After the end of World War II, Germany had been divided into four occupation zones. The old capital of Berlin, as the seat of the Allied Control Council, was itself subdivided into four occupation zones. Although the intent was for the occupying powers govern Germany together, when the Cold War began the French, British and American zones formed the Federal Republic of Germany (including West Berlin) while the Soviet zone formed the German Democratic Republic in 1949.
A first proposal for German reunification was advanced by Stalin in 1952 under terms similar to those adopted for Austria. It called for the creation of a neutral Germany with an eastern border on the Oder-Neisse line and all allied troops removed within the year. The West German government under Konrad Adenauer favored closer integration with western Europe and asked that the reunification be negotiated with the provision that there be internationally monitored elections throughout Germany. This condition was rejected by the Soviets.
The End of the Division
By the mid-1980s, the prospect of German reunification was widely regarded within both Germanies as a distant hope, unattainable as long as communists ruled Eastern Europe. This hope was suddenly placed within reach by political changes within the Soviet Union.
In August 1989, Hungary removed its border restrictions with Austria and in September more than 13,000 East Germans escaped to the West through Hungary. Mass demonstrations against the East German regime began in late 1989, most prominently the Monday demonstrations in Leipzig. Erich Honecker resigned in October, 1989. The travel restrictions for East Germans were removed by the new government on November 9, 1989, and many people immediately went to the Wall where the border guards opened access points and allowed them through.
Germany was officially reunified on October 3, 1990, when the five reestablished federal states (Bundesländer) of East Germany formally joined the Federal Republic of Germany (West Germany), choosing one of two options implemented in the West German constitution (Grundgesetz). As the new founded German states formerly joined the Federal Republic, the area in which the Grundgesetz (basic law) served as constitution was simply extended. The other choice would have been for East Germany to join as a whole along the lines of a formal union between two German states that then would have had to, amongst other things, create a new consitution for the new founded country. Though the option chosen clearly was simpler, it is and has been responsible for sentiments in the East of being "occupied" or "taken over" by the old Federal Republic.
The cost of reunification has been a heavy burden to the German economy, and has contributed to Germany's inability today to be the locomotive of the European economy that it had been in the past. The costs amounts to over €1.5 trillion (= €1500 billion = US$1835· 109). Following reunification, Germany followed the social policies of Geschichtsaufarbeitung (working through history) and Vergangenheitsbewältigung (mastering the past) to deal with their violent history.