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 October 1990. It was negotiated in 1990 between the 'two', the Federal Republic of Germany and the German Democratic Republic, in addition to 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. The treaty supplanted the 1945 Potsdam Agreement: in it, the Four Powers renounced all rights they had held with regard to Germany, allowing for its reunification as a fully sovereign state the following year. Additionally, the two German states agreed to reconfirm the existing border with Poland, accepting that German territory post-reunification would consist only of what was presently administered by West and East Germany—renouncing explicitly any possible claims to the former eastern territories of Germany including East Prussia, most of Silesia, as well as the eastern parts of Brandenburg and Pomerania.

The entirety of Germany was occupied and administered by the Allies of World War II from the Berlin Declaration on 5 June 1945 to the establishment of West Germany on 23 May 1949. Unlike occupied Japan, Germany was stripped of its sovereignty and former state: after Nazi Germany surrendered on 8 May 1945, four countries representing the Allies asserted joint authority and sovereignty through the Allied Control Council (ACC). At first, Allied-occupied Germany was defined as all territories of Germany before the 1938 Nazi annexation of Austria; the Potsdam Agreement on 2 August 1945 defined the new eastern German border by giving Poland and the Soviet Union all regions of Germany east of the Oder–Neisse line and divided the remaining "Germany as a whole" into four occupation zones, each administered by one of the Allies.