On 18 March 1990, the first free elections in 40 years were held in the GDR. Lothar de Maiziere became Prime Minister, heading a grand coalition made up of the CDU, DSU, DA, SPD and FDP. With him the Bonn government agreed on a timetable for monetary, economic and social union with effect from 1 July 1990, it having become palpably clear that the GDR had no economic basis on which to continue alone and that the majority of the people in the GDR wanted accession to the Federal Republic.

In August 1990 the Volkskammer (the GDR parliament) voted in favor of accession as soon as possible, and on 31 August GDR State Secretary Gunter Krause and Federal Minister of the Interior Wolfgang Schauble were able to sign the “Unification Treaty”. Thus on 3 October 1990 the German Democratic Republic officially acceded to the Federal Republic in accordance with Article 23 of the Basic Law. The - newly reestablished - GDR states of Brandenburg, Mecklenburg-Western Pomerania, Saxony, Saxony-Anhalt and Thuringia became states (Lander) of the Federal Republic of Germany. Berlin was made the capital and the Basic Law, after appropriate amendments, entered into force in the territory of the former GDR as well.

The road to unity had been opened by General Secretary Mikhail Gorbachev, who had given his approval after talks with Chancellor Helmut Kohl in Moscow and in the Caucasus in July 1990. He did so on the condition that the Federal Republic would forgo ABC weapons and reduce its forces to 370,000, and that NATO’s military organization would not be extended to GDR territory as long as Soviet forces remained stationed there. The two leaders also agreed that the Soviet troops would be withdrawn from eastern Germany by the end of 1994 and that the Federal Republic would provide financial support for their repatriation.