February 1st, 1945: President Roosevelt is informed of the successful detonation of the Trinity Nuclear Device, talks with the Soviets immediately shift from ceding Eastern Europe in exchange for an invasion of Japan, to allowing the Soviets to administer their Pre-Barbados claims over the Eastern half of Poland.
March 3rd, 1945: President Roosevelt and Winston Churchill meet with Chariman Chiang_Kai-shek, and Mao Zedong leader of the Chinese Liberation Army, in Rangoon. In exchange for arms and political reforms by the Chinese government, Mao agrees to work with the allies in Asia to drive the Japanese out of Manchuria.
March 12th, 1945: President Roosevelt gives the order to drop the atomic bomb on Nagasaki and Hiroshima. WWII ends with Japan's unconditional surrender.
March 20th, 1945: Winston Churchill visits the United States to meet with President Roosevelt for what will be the last time. The two discuss the proposed decolonization protocols of the new United Nations. Churchill informs Roosevelt that he intends to create a Kurdish state to act as a buffer against the Soviets in the Caucasus.
April 3rd, 1945: President Roosevelt, sends his proposed Second Bill of Rights to the US Congress. China officially ratifies its new constitution, creating greater representation for the Chinese people and popular elections for a President.
April 12th, 1945: President Roosevelt dies, he is succeeded by Vice President Henry A. Wallace. The allies of WWII hold multiple morning ceremonies.
January 1946: The UN passes the decolonization acts, Indochina is the first nation to be granted independence from France.
This was originally from an Alternate Timeline I wrote called Engine of Progress, but I've always enjoyed the general idea of a Cold War where Yalta didn't condemn half of Europe to the Soviets.
BTW: This is an alternate map of the world in 1980.