"The atomic age began on August 6, 1945, when the United States dropped its first nuclear bomb on Hiroshima, killing more than seventy thousand people, injuring an equal number, and destroying four square miles of Japan’s eighth-largest city. Three days later the United States dropped an equally destructive bomb on Nagasaki. At the time Truman’s decision to use nuclear weapons to end the war quickly was scarcely questioned. Yet almost immediately afterward, the world public recognized a quantum change in modern warfare: a device threatening human life and the earth itself. Truman’s supporters insisted that the bomb had saved the hundreds of thousands of American lives that would have been lost in an amphibious invasion of the Japanese mainland and pointed to the even worse bombing atrocities during the war. His critics protested the callous and even unnecessary destruction of an enemy about to collapse, when either a demonstration test or a blockade could have convinced Japan to capitulate. Some also suspected that this US show of force was designed to intimidate Stalin and check Soviet designs in Europe, Asia, and the rest of the world."