West Germany also abandoned for the time being its claims with respect to German self-determination and reunification, recognising the existence of the German Democratic Republic (GDR); and the validity of the Oder–Neisse line in international law."[42] As part of this new approach, West Germany concluded friendship treaties with the Soviet Union (Treaty of Moscow (1970)), Poland (Treaty of Warsaw (1970)), East Germany (Basic Treaty (1972)) and Czechoslovakia (Treaty of Prague (1973)); and participated in the Helsinki Final Act (1975). Nevertheless, West Germany continued its long term objective of achieving a reunification of East Germany, West Germany and Berlin; and maintained that its formal recognition of the post-war boundaries of Germany would need to be confirmed by a united Germany in the context of a Final Settlement of the Second World War. Some West German commentators continued to maintain that neither the Treaty of Zgorzelec nor the Treaty of Warsaw should be considered as binding on a future united Germany; albeit that these reservations were intended for domestic political consumption, and the arguments advanced in support of them had no substance in international law.