During the postwar era, the Federal Republic of Germany also sought to improve its relationship with the countries of eastern Europe, first establishing trade agreements and, subsequently, diplomatic relations. With unification, German relations with the new democracies in central and eastern Europe intensified. On November 14, 1990, Germany and Poland signed a treaty confirming the Oder-Neisse border. They also concluded a cooperation treaty on June 17, 1991. Germany concluded four treaties with the Soviet Union covering the overall bilateral relationship, economic relations, the withdrawal of Soviet troops from the territory of the former G.D.R., and German support for those troops. Russia accepted obligations under these treaties as successor to the Soviet Union. Germany continues to be active economically in the states of central and eastern Europe and to actively support the development of democratic institutions, bilaterally and through the EU.

During the years of Berlin's isolation--176 kilometers (110 mi.) inside the former G.D.R.--the Western Allies encouraged a close relationship between the Government of West Berlin and that of the F.R.G. Representatives of the city participated as nonvoting members in the F.R.G. parliament; appropriate West German agencies, such as the supreme administrative court, had their permanent seats in the city; and the governing mayor of Berlin took his turn as President of the Bundesrat. In addition, the Allies carefully consulted with the F.R.G. and Berlin Governments on foreign policy questions involving unification and the status of Berlin.

Between 1948 and 1990, major events such as fairs and festivals took place in West Berlin, and the F.R.G. encouraged investment in commerce by special concessionary tax legislation. The results of such efforts, combined with effective city administration and the Berliners' energy and spirit, were encouraging. Berlin's morale remained high, and its industrial production considerably surpassed its prewar level.

The Final Settlement Treaty ended Berlin's special status as a separate area under Four Power control. Under the terms of the treaty between the F.R.G. and the G.D.R., Berlin became the capital of a unified Germany. The Bundestag voted in June 1991 to make Berlin the seat of government. The Government of Germany asked the Allies to maintain a military presence in Berlin until the complete withdrawal of the Western Group of Forces (ex-Soviet) from the territory of the former G.D.R. The Russian withdrawal was completed August 31, 1994. On September 8, 1994, ceremonies marked the final departure of Western Allied troops from Berlin.

In 1999, the formal seat of the federal government moved from Bonn to Berlin. Berlin also is one of the Federal Republic's 16 Laender.