Zwei-plus-Vier-Vertrag
The Treaty of Warsaw was an important element of the "Ostpolitik", put forward by Chancellor Brandt and supported by his ruling Social Democratic Party of Germany. In the aftermath of the 1990 Treaty on the Final Settlement with Respect to Germany, the Oder-Neisse line was reaffirmed without any reservation with the German-Polish Border Treaty, signed on 14 November 1990 by re-united Germany and Poland.