Perhaps the main point of the Yalta Agreement was that the United Nations would be created. This was certainly among Roosevelt's biggest priorities, who saw it as a way of ensuring that the United States did not revert to an isolationist stance after the war. Another major result was an agreement that Poland would receive substantial territory to make it a stronger buffer state. To achieve this, Stalin agreed to swift elections in a new, free Poland, and that the government of Poland should be what was rather vaguely described as "democratic." The nations, mainly the USSR, Great Britain, and the United States, agreed to spheres of influence in newly liberated Eastern Europe, with the United States having sway in Greece, the USSR in Romania and Bulgaria, and shared influence in the Balkans. Other agreements involved Germany, which the sides tentatively agreed would be divided into four military occupation zones. Finally, Stalin agreed to enter the war against Japan within three months of Germany's surrender.