If you have ever noticed a German flag flown from a public building on October 3, you are looking at a country that, on that date in 1990, formally stopped being two countries. Reunification took effect at midnight on October 2, with the public celebrations beginning the next morning on the German national holiday of the Tag der Deutschen Einheit. On that day the five re-established Länder of the former GDR — Brandenburg, Mecklenburg-Vorpommern, Sachsen, Sachsen-Anhalt, and Thüringen — acceded to the Federal Republic under Article 23 of the Basic Law, extinguishing the Basic Treaty of December 21, 1972 that had been the only remaining legal complication.
The reunification was the consequence of the Wall’s fall, but the pace of the process was faster than the fall itself. From the open of the Wall on November 9, 1989 to the accession of October 3, 1990 was less than eleven months. The two most important steps along the way were the Volkskammer elections of March 18, 1990 and the Two Plus Four Agreement of September 12, 1990. The diplomatic process is the subject of Mary Elise Sarotte’s Not One Inch (2021); the German-language standard work is Werner Weidenfeld’s Außenpolitik für die deutsche Einheit (1994).
The Path from the Wall
The East German leadership tried to slow the process. Hans Modrow, the new prime minister, proposed a German confederation. Helmut Kohl’s Ten Points speech of November 28, 1989 proposed a three-stage transition through confederal relations to federation to “a federation, that is, a united Germany.” The two proposals were not as different as they initially sounded; the difference was in the timeline. Modrow’s confederation would have left the GDR in place. Kohl’s federation would have incorporated it.
The decisive shift came with the Volkskammer elections of March 18, 1990. The Alliance for Germany — a coalition of the East German CDU, the Democratic Awakening, and the German Social Union — won 48 percent of the vote and a clear majority in the Volkskammer. The two smaller parties in the new government (the FDP and the SPD) were also committed to reunification, on similar terms. The voters were not. The Party of Democratic Socialism, successor to the ruling Socialist Unity Party, won only 16 percent. The Platform of the Left and the United Left, both opposed to reunification on the West German terms, did worse.
The new East German government moved quickly. Negotiations with the Federal Republic produced a State Treaty on May 18 establishing a monetary, economic, and social union, which took effect on July 1, 1990. The treaty replaced the East German mark with the West German mark at parity, an act of generosity that has been criticized by economists ever since. The two governments also agreed on a Unification Treaty, signed on August 31, 1990, which provided the legal framework for accession under Article 23.
The Two Plus Four Process
The external settlement was the work of the two German governments and the four wartime powers: the United States, the Soviet Union, the United Kingdom, and France. The process that took their name was diplomatic: foreign-minister level meetings in Bonn (May 5), Berlin (June 22), and Paris (July 17) before the ministerial meeting in Moscow that produced the agreement on September 12, 1990.
The key questions were five. The first was the borders: a unified Germany would consist of the territory of the Federal Republic, the GDR, and Berlin, with the post-1945 borders confirmed and the Oder-Neisse line as the eastern border. The second was the military status: a unified Germany would belong to NATO, with the understanding that NATO forces would not be deployed into the former East Germany, the so-called “no deployment” commitment. The third was the Soviet troop withdrawal: the roughly 380,000 Soviet military personnel in the GDR would be withdrawn by 1994, with Germany paying an estimated 12 billion Deutsche Mark in transit and housing costs. The fourth was the arms control regime: Germany would renounce nuclear, biological, and chemical weapons and accept the limits of the INF Treaty and START I. The fifth was the question of recognition: the four powers would terminate their rights and responsibilities with respect to Germany and Berlin as of the date of accession.
The most difficult negotiation was with the Soviet Union. The “no deployment” commitment was the price of Soviet acceptance. The troop withdrawal was the question of cost. The German government ultimately paid 12 billion Deutsche Mark and provided substantial logistical support for the withdrawal. Gorbachev, weakened politically and economically, accepted the package in late August 1990. The agreement was signed by the foreign ministers on September 12, 1990.
The Unification Treaty and the Accession
The Unification Treaty, signed on August 31, 1990, was a detailed legal document with 45 articles and many annexes. It transferred the territory of the GDR to the Federal Republic under Article 23 of the Basic Law, providing for the accession of the five re-established Länder on October 3, 1990. It provided for the expansion of the Bundestag and the Bundesrat to include representatives from the new Länder, for the application of West German law in the former GDR, and for the continuation of certain East German welfare provisions. The most controversial provisions concerned property — the restitution of property expropriated between 1949 and 1990 — and abortion, which the new Länder would not be permitted to liberalize.
The Volkskammer voted to approve the Unification Treaty on September 20, 1990, by 294 votes to 62. The Bundestag and the Bundesrat approved it the same week. The Allied reservations on Germany and Berlin were extinguished on October 1. The accession took effect on October 3. The date was chosen because it was a Wednesday (so as not to disrupt weekend plans) and because it was the eleventh anniversary of the original Basic Law.
The Aftermath
The unification of October 3, 1990 closed the formal division. The economic and social unification of the two Germanys is a separate story, and it is still being written. The first decade produced a transfer of roughly 1.5 trillion Deutsche Mark in federal funds to the new Länder. The East German economy contracted by roughly a third in 1990–91, and the productivity gap with the West, while narrowing, has remained significant. The wage gap is roughly 80–85 percent. The political gap, on most indicators of democratic attitudes, has narrowed as well, though populist parties of the AfD kind have been stronger in the East than in the West.
The cultural and political settlement of the East German past is also ongoing. The Federal Foundation for the Reappraisal of the SED Dictatorship, established in 1998, has funded research, education, and memorial projects. The Stasi Records Agency (the BStU, now part of the Federal Archives) made roughly 110 kilometers of files available to former victims. The Berlin Wall Memorial, opened in 1998 and expanded since, is the principal site of memory. The unification was the end of the political crisis of 1989. The integration of the two Germanys is a project of decades, and it continues.