In addition to his lighter attitude towards post-war Germany, Roosevelt hoped to gain the support of his counterparts for his proposal to extend the formal alliance of the main signatories to the January 1942 “United Nations Declaration” (United States, Soviet Union, Great Britain and China) as a world peacekeeping organization until the post-war period. Stalin was not enthusiastic about the plan and expressed doubts about China`s importance in a post-war order, but the three leaders eventually committed to it. In Tehran, the three Allied leaders also discussed important issues on the fate of Eastern Europe and Germany in the post-war period. Stalin insisted on a revision of Poland`s eastern border with the Soviet Union to comply with the line of the British Foreign Secretary, Lord Curzon, in 1920. In order to compensate Poland for the resulting loss of territory, the three heads of state and government agreed to move the German-Polish border to the Oder and Neisse. However, this decision was not formally ratified until the Potsdam Conference in 1945. During these negotiations, Roosevelt Stalin also assured that the republics of Lithuania, Latvia and Estonia would not be reintegrated into the Soviet Union until after the citizens of each republic had voted on the issue in a referendum. Stalin stressed, however, that the issue had to be resolved “in accordance with the Soviet Constitution” and that he would not accept any international control over the elections. Roosevelt, Churchill and Stalin also raised the issue of a possible post-war division of Germany into Allied zones of occupation and said they were ready to have the issue of dismemberment “carefully” considered by the European Advisory Commission before a final decision was taken. The three governments recognize that the war has posed particular economic difficulties for Iran and have all agreed that they will continue to provide the Iranian government with the most important economic assistance possible, given the high demands placed on them by their global military operations. and the global shortage of transport, raw materials and supplies for civilian consumption.  The Tehran Conference (codenamed Eureka) was a strategic meeting of Joseph Stalin, Franklin D. Roosevelt and Winston Churchill from November 28 to December 1, 1943, after the Anglo-Soviet invasion of Iran.
It took place at the Soviet Embassy in Tehran, Iran (Persia). It was the first of the conferences of the “Big Three” Allied leaders (Soviet Union, United States and United Kingdom). She was closely following the Cairo conference that took place from 22 to 26 November 1943 and preceded the Yalta and Potsdam conferences in 1945. Although the three leaders arrived with different objectives, the most important of the Tehran conference was the commitment of the Western Allies to open a second front against Nazi Germany.