1945: The Big Three Divide up Europe
With the war in Europe nearing a conclusion with the expected defeat of Nazi Germany, the leaders of the United States, Great Britain, and the Soviet Union agreed to meet to discuss the future of post-war Europe.

The Yalta Conference
On February 4, 1945, American President Franklin D. Roosevelt, British Prime Minister Winston Churchill, and Soviet Premier Josef Stalin arrived in the Crimean resort town of Yalta on the Black Sea. When the meetings concluded a week later, the three leaders had reached agreements that would establish the conditions that led to the start of the Cold War.

The three leaders agreed to divide post-war Germany, and Germany's capital, Berlin, into four zones. The zones would be controlled by the United States, Great Britain, France, and the Soviet Union.

Roosevelt and Churchill also agreed that the nations of Eastern Europe on the western border of the Soviet Union should be "friendly" to the Soviet government. In return, Stalin pledged to allow free elections in those countries, a pledge he soon broke as the nations of Eastern Europe came under Soviet domination. The millions of people who lived behind what Churchill would call the "Iron Curtain" would spend 45 years under the control of the Soviet Union and the Communist Party.

Although the Soviets did not expand their "sphere of influence" into Western Europe, it clearly sought to expand communism beyond Eastern Europe. In response, President Harry S. Truman announced what came to be called the Truman Doctrine.

President Truman's policy committed the United States to "...support free peoples who are resisting attempted subjugation by armed minorities or outside pressures." Also known as "containment," the Truman Doctrine was a clear signal to the Soviet Union that the United States would oppose further Soviet expansionism.