On August 6, 1945, an American plane dropped an atomic bomb over the city of Hiroshima. The bomb flattened four square miles and instantly killed more than 70,000 people. In the months that followed, many more would die from radiation sickness, a deadly aftereffect of exposure to radioactive materials.
Truman warned the Japanese that if they did not surrender, they could expect “a rain of ruin from the air, the like of which has never been seen on this Earth.” And on August 8, the Soviet Union declared war on Japan and invaded Manchuria. Again, Japanese leaders did not respond. The next day, the United States dropped a second atomic bomb, this time on the city of Nagasaki. More than 40,000 people were killed in this second explosion.
Some members of the Japanese cabinet wanted to fight on. Other leaders disagreed. Finally, on August 10, Emperor Hirohito intervened, an action unheard of for a Japanese emperor. He forced his government to surrender. On September 2, 1945, the formal peace treaty was signed on board the American battleship Missouri, anchored in Tokyo Bay. After more than five years of fighting, World War II was over.
After Japan failed to accept Allied surrender terms, Truman ordered the atomic bombings of Hiroshima and Nagasaki. The destruction was unlike anything the world had seen.
Using the atomic bomb against Japan brought a quick end to World War II. It also unleashed terrifying destruction. Ever since, people have debated whether or not the United States should have used the bomb.
For President Truman, using the bomb was a difficult decision. He later explained that he made his decision based only on military considerations. He was concerned that Japan would not surrender without an invasion, and that would cost an enormous loss of lives. After all, the Japanese still had a home army of 2 million.
Critics of Truman's decision argued that Japan was almost defeated at that point and the bomb was not needed. They also claim that by using the atomic bomb, the United States unleashed a dangerous arms race that grew over the next decades.
Growing differences between the United States and the Soviet Union may also have influenced Truman's decision. Truman may have hoped the bomb would impress the Soviets with American power. The debate over Truman's decision has continued to the present.
What was the purpose of the declaration issued by the Allies at Potsdam?
Even as the Allies celebrated victory, the appalling costs of the war began to emerge. The war had killed as many as 50 million people around the world. In Europe alone, over 30 million people had lost their lives, more than half of them civilians. The Soviet Union suffered the worst casualties, with over 20 million dead.
“Give me ten years and you will not be able to recognize Germany,” Hitler had predicted in 1933. Indeed, Germany in 1945 was an unrecognizable ruin. Parts of Poland, the Soviet Union, Japan, China, and other countries also lay in ruins. Total war had gutted cities, factories, harbors, bridges, railroads, farms, and homes.
Over 20 million refugees wandered Europe. Amid the devastation, hunger, disease, and mental illness took their toll for years after the fighting ended. As they had after World War I, the Allies faced difficult decisions about the future.
Numbers alone did not tell the story of the Nazi nightmare in Europe or the Japanese brutality in Asia. During the war, the Allies were aware of the existence of Nazi concentration camps and death camps.