The last part of World War II was the birth of the atomic age. The United States dropped atomic bombs on Hiroshima and Nagasaki, forcing Japan to surrender. The United States emerged from the wreckage of the war as the leader of the Western world. Veterans returned to their homes, families, schools, and jobs. The United States was poised to become one of the greatest economic powers in history. However, there was an increasing anxiety caused by the atomic bomb and the beginning of the Cold War with the Soviet Union.

On March 5, 1946, Winston Churchill, the prime minister of Great Britain, gave a speech at Westminster College in Fulton, Missouri, in which he declared: "From Stettin in the Baltic to Trieste in the Adriatic an iron curtain has descended across the Continent." Churchill warned that the United States and its allies had to be...