How did differing ideas lead to the world splitting into two factions after ww2

Despite their wartime alliance, tensions between the Soviet Union and the United States and Great Britain intensified rapidly as the war came to a close and the leaders discussed what to do with Germany. Post-war negotiations took place at two conferences in 1945, one before the official end of the war, and one after. These conferences set the stage for the beginning of the Cold War and of a divided Europe.