The Treaty on the Final Settlement with Respect to Germany (), or the Two Plus Four Agreement (;), is an international agreement that allowed the reunification of Germany in the early 1990s. It was negotiated in 1990 between the Federal Republic of Germany and the German Democratic Republic (the eponymous Two), and the Four Powers which had occupied Germany at the end of World War II in Europe: France, the Soviet Union, the United Kingdom, and the United States; it also replaced the 1945 Potsdam Agreement before. In the treaty, the Four Powers renounced all rights they held in Germany, allowing a reunited Germany to become fully sovereign the following year. At the same time, the two German states agreed to confirm their acceptance of the existing border with Poland, and accepted that the borders of Germany after unification would correspond only to the territories then administered by West and East Germany, with the exclusion and renunciation of any other territorial claims (e.g., to the former eastern territories of Germany, including Silesia and East Prussia as well as the eastern parts of Brandenburg and Pomerania). Background On 1 August 1945, the Potsdam Agreement, promulgated in the Potsdam Conference, among other things agreed on the initial terms under which the Allies of World War II would govern Germany. A provisional German–Polish border known as the Oder–Neisse line awarded, in theory within the context of that "provisional border", most of Germany's former eastern provinces to Poland and the Soviet Union. The German populations of these areas either fled or were expelled. Although the German Democratic Republic formally accepted the border in the 1950 Treaty of Zgorzelec with Poland, West Germany initially entirely rejected it, declaring the treaty ″null and void″ in line with the Hallstein Doctrine, and later reluctantly recognised the border in the 1970 Treaty of Warsaw as provisional only, to be finalised by "a peace settlement for Germany to be accepted by the Government of Germany when a government adequate for the purpose is established" (Potsdam Agreement 1.3.1). Parts of those above-mentioned agreements were burdened with controversy from several sources e.g., Churchill's comment about "stuffing the Polish goose too full" (of German lands). The overall "German Question" became one of the salient and crucial issues of the long-running Cold War, and until it ended in the late 1980s, little progress had been made in the establishment of a single government