Irish Taoiseach Charles Haughey supported German reunification and took advantage of the Irish Presidency of the European Economic Community to call for an extraordinary European summit in Dublin in April 1990 to allay the fears of his EEC colleagues.    Haughey saw similarities between Ireland and Germany and stated, „I have personally expressed the opinion that many of us, if we come from a country that is equally divided, would have sympathy for any desire for unification of the people of the two German states.“  Der Spiegel later described the views of other European heads of state and government on reunification at the time as „frosty.“ Italy`s Giulio Andreotti warned of a revival of „pan-Germanism,“ joking: „I love Germany so much that I`d rather see two,“ and Dutchman Ruud Lubbers questioned Germany`s right to self-determination. They shared the concerns of Britain and France regarding a return to German militarism and the economic power of a reunified nation. Thatcher, who carried a map of Germany`s 1937 borders in her purse to show others the „German problem,“ feared that its „national character,“ size, and central location in Europe would make the nation a „destabilizing rather than stabilizing force in Europe.“  In December 1989, she warned the other Heads of State or Government of the European Community at a summit in Strasbourg attended by Kohl: „We have defeated the Germans twice! And now they`re back!   Although Thatcher declared her support for German self-determination in 1985, she now argues that Germany`s allies supported reunification only because they did not believe it would ever happen.  Thatcher was in favour of a five-year transitional period for reunification, during which the two Germans would remain separate states. Although she gradually weakened her resistance, Thatcher summoned historians and diplomats to a seminar in Chequers in March 1990 to ask, „How dangerous are the Germans?“  and the French ambassador in London reported that Thatcher had told him: „France and Britain should unite today in the face of the German threat.“   For decades, the West German allies have been committed to reunification. Israeli Prime Minister Yitzhak Shamir, who speculated that a country that „decided to kill millions of Jews“ in the Holocaust „will try to do it again,“ was one of the few world leaders to publicly oppose it. However, when reunification became a realistic possibility, a significant opposition between NATO and Europe appeared in private.  Constitutionally, the Basic Law provided for two ways of unification.
The first was the implementation of a new all-German constitution, which was obtained by referendum. In fact, this was the original idea of the „Basic Law“ of 1949: it was called the „Basic Law“ instead of the „Constitution“ because it was considered provisional.  The second route was more technical: the implementation of the Constitution in the East using a paragraph initially intended for the West German Länder in the event of an internal reorganization such as the merger of two states. Although the latter option was chosen as the most viable, the former option was seen in part as a means of promoting „internal reunification“.   The chosen procedure was one of the two options implemented in the 1949 Basic Law to facilitate possible reunification. The Basic Law stipulated that it was intended only for temporary use until a permanent constitution could be adopted by the entire German people. Thanks to Article 23 (then existing) of this document, all new future federal states could accede to the Basic Law by a simple majority. The first eleven acceding states of 1949 formed the Trizone. West Berlin had been proposed as the 12th state, but was legally inhibited by the objections of the Allies, since Berlin as a whole was legally occupied territory on four levels.
Nevertheless, West Berlin`s political affiliation with West Germany was, and in many areas, it functioned de facto as if it were part of West Germany. In 1957, the Saar Protectorate joined the Federal Republic of Germany as Saar under the Article 23 procedure. On the 28th. In November 1989, two weeks after the fall of the Berlin Wall, Chancellor Helmut Kohl announced a 10-point programme calling on the two German states to expand their cooperation with a view to possible reunification.  Although even then, many at home and abroad believed that true reunification would never take place in the foreseeable future.  The turning point in Germany, called „Die Wende,“ was marked by the „Peaceful Revolution“ that led to the demolition of the Berlin Wall, with East and West Germany subsequently entering into negotiations to eliminate the division imposed on Germans more than four decades earlier. The pace of events surprised the Frenchman, whose Foreign Ministry concluded in October 1989 that reunification „does not seem realistic at the present time.“  A representative of French President François Mitterrand reportedly told an adviser to Gorbachev: „France does not want German reunification, although it recognizes that in the end it is inevitable.“  At the Strasbourg summit, Mitterrand and Thatcher discussed the fluidity of Germany`s historic borders.  On January 20, 1990, Mitterrand told Thatcher that a united Germany could „catch up more ground than even Hitler.“  He predicted that „bad“ Germans would reappear, who might try to reconquer the former German territory that had been lost after World War II and who would likely dominate Hungary, Poland, and Czechoslovakia, leaving „only Romania and Bulgaria for the rest of us.“ .