Ostpolitik

Neue Ostpolitik (German for "new eastern policy"), or Ostpolitik for short, was the normalization of relations between the Federal Republic of Germany (FRG, or West Germany) and 
Eastern Europe, particularly the German Democratic Republic (GDR, or East Germany) beginning in 1969. Influenced by Egon Bahr, who proposed "change through rapprochement" in a 1963 speech at the Evangelische Akademie Tutzing, the policies were implemented beginning with Willy Brandt, fourth Chancellor of the FRG from 1969 to 1974.
"Ostpolitik" was an effort to break with the policies of the Christian Democratic Union (CDU), which was the elected government of West Germany from 1949 until 1969. The Christian Democrats under Konrad Adenauer and his successors tried to combat the Communist government of East Germany, while Brandt's Social Democrats tried to achieve a certain degree of cooperation with East Germany.
The term "Ostpolitik" has since been applied to Pope Paul VI's efforts to engage Eastern European countries during the same period. The term "Nordpolitik" was also coined to describe similar rapprochement policies between North and South Korea beginning in the 1980s.
Intention.
Following the end of World War II in 1945, Allied-occupied Germany was split into two states: the Federal Republic of Germany (FRG, or West Germany) and the German Democratic Republic (GDR, or East Germany). Initially, both governments claimed that they represented the entire German nation. However, the Federal Republic saw itself as the only German government with democratic legitimacy. Later, at the end of the 1960s, the communist government of the GDR claimed that there was no longer a common German nation as the GDR had established a socialist nation.
The Christian Democratic Union (CDU) political party dominated West German governments from 1949 to 1969. These governments refused to have any contact with the GDR government due to its undemocratic character, and the Hallstein Doctrine stipulated that the FRG would withdraw diplomatic contact from any country that established diplomatic relations with the GDR. The first application of the Hallstein Doctrine was in 1957, when the FRG withdrew recognition of Yugoslavia after it accepted a GDR ambassador. In the 1960s it became obvious that this policy would not work forever. When the Federal Republic established diplomatic relations with Israel in 1965, the Arab states countered by breaking off relations with the Federal Republic and establishing relations with the GDR.
Even before his election as Chancellor, Willy Brandt, the Social Democratic mayor of West Berlin, argued for and pursued policies that would ease tensions between the two German states, generally in the interest of cross-border commerce. His proposed new "Ostpolitik" held that the Hallstein Doctrine did not help to undermine the communist government or even lighten the situation of the Germans in the GDR. Brandt believed that collaboration with the communists would foster German-German encounters and trade that would undermine the communist government over the long term.
Nonetheless, he stressed that his new "Ostpolitik" did not neglect the close ties of the Federal Republic with Western Europe and the United States or its membership in NATO. Indeed, by the late 1960s, the unwavering stance of the Hallstein Doctrine was actually considered detrimental to US interests; numerous American advisors and policymakers, most notably Henry Kissinger, urged Bonn to be more flexible. At the same time, other West European countries entered a period of more daring policy directed to the East. When the Brandt government became Chancellor in 1969, the same politicians now feared a more independent German "Ostpolitik", a new "Rapallo". France feared that West Germany would become more powerful after détente; Brandt ultimately resorted to pressuring the French government into endorsing his policy by holding out German financial contributions to the European Common Agricultural Policy.
Realisation.
The easing of tensions with the East envisioned by "Ostpolitik" necessarily began with the Soviet Union, the only Eastern Bloc state with which the Federal Republic had formal diplomatic ties (despite the aforementioned Hallstein Doctrine). In 1970 Brandt signed the Treaty of Moscow, renouncing the use of force and recognizing the current European borders. Later that year, Brandt signed the Treaty of Warsaw, in the process formally recognizing the People's Republic of Poland. The Treaty of Warsaw essentially repeated the Moscow treaty, and in particular reiterated the Federal Republic's recognition of the Oder–Neisse line. Treaties with other Eastern European countries followed.
The most controversial agreement was the Basic Treaty of 1972 with East Germany, establishing formal relations between the two German states for the first time since partition. The situation was complicated by the Federal Republic's longstanding claim to represent the entire German nation; Chancellor Brandt sought to smooth over this point by repeating his 1969 statement that although two states exist in Germany, they cannot regard one another as foreign countries.
The conservative CDU opposition party in the Bundestag refused the Basic Treaty because they thought that the government gave away some Federal positions too easily. They also criticized flaws like the unintentional publishing of the "Bahr-Papier", a paper in which Brandt's right hand Egon Bahr had agreed with Soviet diplomat Valentin Falin on essential issues.
The Brandt government, a coalition of Social Democrats and Free Democrats, lost a number of MPs to the CDU opposition in protest over the Basic Treaty. In April 1972 it even seemed that opposition leader Rainer Barzel had enough support to become the new Chancellor, but in the parliamentary decision he came two votes short. It later emerged that the GDR had paid the two CDU deputies to vote against Barzel.
New general elections in November 1972 gave the Brandt government a victory, and on 11 May 1973 the Federal Parliament approved the Basic Treaty.
According to the Basic Treaty the Federal Republic and GDR accepted each other's de facto ambassadors, termed "permanent representatives" for political reasons. The mutual recognition opened the door for both states to join the United Nations, as the Federal Republic's claim to representing the entire German nation was essentially dropped by the act of recognizing its Eastern counterpart.
The CDU/CSU persuaded the FDP to defect from its coalition with the SPD in 1982, and thus CDU leader Helmut Kohl became Chancellor of West Germany. However, he did not change West German policy towards the GDR. Such was the consensus that "Ostpolitik" had been vindicated that Bavarian Minister-President Franz Josef Strauß, who had fiercely fought against the Basic Treaty and was Kohl's main opponent within the CDU/CSU bloc, secured the passage of a Kohl-initiated loan of 3 billion marks to the GDR in 1983. In 1987, East German leader Erich Honecker became the first ever East German head of state to visit West Germany, which was generally seen as a sign that Kohl pursued "Ostpolitik".
Policies similar to Ostpolitik.
Vatican diplomacy.
"Ostpolitik" is also the name given to Pope Paul VI's policies towards the Soviet Union and its Eastern European satellite states. Trying to improve the condition of Christians in general and Catholics in particular behind the Iron Curtain, he engaged in dialogue with Communist authorities at several levels, receiving Foreign Minister Andrei Gromyko and USSR head of state Nikolai Podgorny in 1966 and 1967 in the Vatican. The situation of the Church in Poland, Hungary and Romania improved somewhat during his pontificate.
South Korea.
South Korea's 1980s policy of "Nordpolitik" was named in allusion to "Ostpolitik".
A similar concept is Sunshine Policy, which is the main North Korea policies of the Democratic Party of Korea.
Taiwan (Republic of China).
Taiwan's China policy of "Mainlandpolitik" is named in allusion to "Ostpolitik".
List of treaties.
These are West German treaties that have "Ostpolitik" as a primary or secondary policy goal:
Later agreements in the period of Christian Democrat Helmut Kohl (from 1982 through German reunification in 1990), although dealing with similar issues and having similar goals, are not considered to be "Ostpolitik".