Postwar discussion of the Danube River was begun by the United States in 1945 when President Truman proposed at the Potsdam Conference that freedom of navigation should be assured on Europe 's inland waterways . Britain and France were concerned with reestablishing their prewar positions as members of the European Commission of the Danube . In 1947 , the Paris peace treaties signed with Romania , Hungary , and Bulgaria guaranteed free navigation.The foreign ministers of Britain , France , the USSR , and the United States stipulated that : Navigation on the Danube shall be free and open for the nationals , vessels of commerce and goods of all states , on a footing of equality in regard to port and navigation charges and conditions for merchant shipping . The foregoing shall not apply to traffic between ports of the same state . The Big Four also decided that a conference should be held within six months after the treaties came into force " to work out a new convention regarding the regime of the Danube . " In February 1948 the United States proposed calling a conference , thus averting a multilateral pact that might have been concluded among the Eastern European countries
Potsdam Conference
Potsdam Conference
Danube River Conference of 1948