Background

A small group of German scientists accidentally discovered nuclear fission in 1938. They observed that a radioactive atom releases a huge burst of energy when it is split. This discovery, they found, could be a powerful weapon of war. As the Nazi government began placing more controls on the German people, many scientists fled Germany. Some came to the United States. They informed the famed scientist Albert Einstein of the power of nuclear fission.

In August 1939, Einstein signed a letter for the United States President Franklin D. Roosevelt. The letter warned the president of a new, potentially dangerous weapon. The Einstein-Szilard letter stated “that the element uranium may be turned into a new and important source of energy in the immediate future … This new phenomenon would also lead to the construction of bombs, and it is conceivable—though much less certain—that extremely powerful bombs of a new type may thus be constructed.” Just one atomic bomb, he believed, “carried by boat and exploded in a port, might very well destroy the whole port together with some of the surrounding territory….” (Einstein).

Einstein’s letter alarmed President Roosevelt. He was concerned Germans could use the weapon against civilians in Europe and America. When Hitler invaded Poland later that year, Roosevelt knew he had to act. As a result, Americans created the Manhattan Project in August 1942. It was a secret mission to harness the power of nuclear fission to create a bomb. Physicist J. Robert Oppenheimer was put in charge of the top-secret project at the New Mexico base. The Manhattan Project was directed by the U.S. military. But it was a joint project that included military professionals, scientists, and private companies.

Roosevelt died just before the war ended in Europe in spring 1945. In July 1945, the Trinity Test confirmed the power and destructiveness of a controlled nuclear fission bomb.

The new American president was Harry S. Truman. Truman sent a final warning to the Japanese emperor. He warned Emperor Hirohito of Japan’s “prompt and utter destruction” if they did not unconditionally surrender to the Allies—the U.S., U.K., Soviet Russia and France. This warning was called the Potsdam Declaration. On August 6, 1945, a B-29 bomber dropped the first atomic bomb on Hiroshima. Known as “Little Boy,” the bomb was dropped from a plane named the Enola Gay. Approximately 80,000 Japanese citizens were killed instantly. The explosion leveled an area that encompassed 5 square miles. But Emperor Hirohito did not surrender. In response, Truman ordered the dropping of a second bomb called “Fat Man.” This bomb hit the city of Nagasaki on August 9, 1945. At least 40,000 Japanese were killed in this attack. Thousands more died in the areas of Hiroshima and Nagasaki in the years ahead due to radiation poisoning from the blasts. Japan finally surrendered to the Allies on August 15, 1945. World War II had officially come to an end.

Those who fought in and lived through World War Two saw some of the most horrific tragedies the world had ever seen. This war was unlike any before. Millions of people died in concentration camps fueled by racism and antisemitism (prejudice against Jewish people). Hundreds of thousands were killed by a new, powerfully deadly atomic bomb. People have long debated if the use of the atomic bomb was the only way to win the war in the Pacific. Truman’s administration claimed it was.

The political-historical debate

Dr. Peter Zimmerman is an American nuclear physicist and former professor at the Department of War Studies at King’s College, London. Zimmerman recently wrote an article titled, “Truman Was Right to Drop the Atomic Bomb.” This passage from the article explains his argument:

“Truman’s choice is often framed as ‘the Bomb or the Invasion,’… Not so; the choice was between the bombs, which might force an end to the war in days, and all other scenarios. The other means to an end of the war were cruel.
A blockade would starve the country. The Soviet invasion of Manchuria and Korea would result in Stalin’s planned occupation of Hokkaido.” U.S. bombing of Japanese cities, using older bombs, “would continue until the Army Air Forces literally ran out of targets. The rail network used to distribute food would be further wrecked.”

Every other option, compared to the atomic bombing of Hiroshima and Nagasaki, would take a very long time, he said.

The blockade by sea was already happening. It “had cut the flow of food from farms in Korea, on Hokkaido, and in Northern Honshu to the Japanese people…”

Food shortages were in effect, Zimmerman notes. When the U.S. occupation began, “the Tokyo food ration was down to 900 calories a day.” In comparison, Nazi concentration camps rationed just 600 calories a day for their prisoners. The Japanese ration was bad enough that the weak and elderly were already dying. “Some in the Imperial government had predicted food riots and civil war by December. But not in August, or September,” Zimmerman continues.

“B-29 bombing raids were destroying one Japanese city every week. Had the war gone on for another month, four or more cities would have been burned to the ground. Roughly one Hiroshima a week.” But by August, he said, the Japanese had gotten used to “relatively slow destruction; there was time to recover somewhat between raids, to extinguish some fires, evacuate some people, and set up some kind of temporary shelter.” Zimmerman believes this lessened the shock of continuing raids.

“As July turned to August, the situation required shock therapy. The slow decline of the Japanese fortunes had to be recast by a sudden and catastrophic event,” continued Zimmerman. The perception in Tokyo, he says, was one of total loyalty to the emperor rather than peace. “Something was needed to change” that view, he said.

“The Allies desperately wanted to avoid invading Japan. Our anticipated death toll was north of 100,000 Allied soldiers and sailors… The battle for Okinawa showed the Allies that Japan would struggle until the last civilian was killed” (Zimmerman).

Many disagree with Truman’s decision and Zimmerman’s explanation. They do not believe that the atomic bomb was less harmful to both Japanese and Allied forces than an invasion. Gar Alperovitz is an American historian. He wrote that Truman’s main goal in dropping the bombs was to intimidate the Soviet Union. The ambassador to the Soviet Union in 1945 was Joseph E. Davies. He met with President Truman in May 1945. It was just two months before the first successful testing of the atomic bomb. In that meeting, Truman revealed that he would be holding off discussions with Stalin about the post-war world until after the results of the tests were completed. Davies wrote, “I was startled, shocked and amazed” about Truman’s decision. In a footnote he wrote, “Uranium—for reason of security I will have to fill this in later” (Alperovitz, 1985).

“On July 16, the first atom bomb was tested successfully at Alamogordo, N.M. On July 17, Truman sat down to talk with Stalin. And on Aug. 6, a bomb would fall on Hiroshima, ultimately killing an estimated 130,000 Japanese and changing the world…

“Most Americans assume the reason Hiroshima and Nagasaki were destroyed was simply to prevent a costly invasion of Japan,” Alperovitz said.

However, some believe that other considerations were involved. The new weapon’s impact on diplomacy toward the Soviet Union was one possible reason. Released documents have strengthened this theory.

“The invasion of Japan—which President Truman claimed might cost up to a million casualties—was scheduled to begin on Nov. 1… (Documents of the time suggest that many planners foresaw far fewer casualties.)

But by the mid-summer of 1945 Japan was in a very bad way. How allied intelligence understood the situation at the time was detailed in a report to the American and British Combined Chiefs of Staff…

‘The increasing effects of sea blockade and cumulative devastation wrought by strategic bombing… has already rendered millions homeless and has destroyed from 25 percent to 50 percent of the built-up area of Japan’s most important cities… A conditional surrender… might be offered by them at any time…’

Admiral William D. Leahy, who served as chief of staff to the President and presided over the Joint Chiefs of Staff, wrote in his diary in mid-June that ‘at the present time… a surrender of Japan can be arranged with terms that can be accepted by Japan and that will make fully satisfactory provision for America’s defense against future trans-Pacific aggression.’ Afterward, Leahy would reflect that ‘the use of this barbarous weapon at Hiroshima and Nagasaki was of no material assistance in our war against Japan…’”

Likewise, Eisenhower would later state that ‘it wasn’t necessary’ to hit the Japanese ‘with that awful thing’” (Alperovitz, 1985).

There is a third theory as to why the Americans used the atomic bombs on Japan. It also supports the idea that the bombing was used to pressure the Soviet Union. Professor Tsuyoshi Hasegawa is a Japanese American historian at the University of California, Santa Barbara. He wrote the book Racing the Enemy: Stalin, Truman, and the Surrender of Japan (2005). Hasegawa shows how the Soviet Union played both sides to attempt to gain territories in Asia during World War II. He proposes that Japan did not unconditionally surrender because of the American’s atomic bombs. Hasegawa believes they surrendered because the Soviet Union had entered the war against Japan.

“…Stalin was an active participant, not a secondary player, as historians have hitherto depicted, in the drama of Japan’s surrender. He was engaged in skillful Machiavellian diplomacy1 to manipulate Japanese desires for a negotiated peace to his own ends. He was involved in intense negotiations with the Americans and reacted
decisively to American maneuvers. He bullied the Chinese into accepting the Soviet terms, and ruthlessly pursued diplomacy and military operations to secure the territories to which he felt entitled.

The study also casts the Americans use of the atomic bomb in a wider setting. The bomb provided a solution to the previously unsolvable dilemma that faced Truman: to achieve Japan’s unconditional surrender before Soviet entry into the war. Truman issued the Potsdam Proclamation, not as a warning to Japan, but to justify the use of the atomic bomb. I challenge the commonly held view that the atomic bomb provided the immediate and decisive knockout blow to Japan’s will to fight. Indeed, the Soviet entry into the war played a greater role than the atomic bombs in inducing Japan to surrender” (Hasegawa, 5).

In fact, Prince Konoe admitted that defeat was near as early as February 1945. At the time, Prince Konoe was the Prime Minister of Japan. He made the admission to Emperor Hirohito.

“While the Big Three were meeting at Yalta on February 14, Konoe submitted his memorandum to Hirohito. ‘I regret to say that Japan’s defeat is inevitable,’ the prince began. ‘Defeat will damage the kokutai,2 but public opinion in America and England has not gone far enough to destroy the kokutai… Therefore, we should not be worried about defeat itself. What we must worry about is a Communist revolution that might accompany defeat.’ Konoe then indicated that the Soviet Union would be interested in expanding its influence in Asia, just as it had in eastern Europe. Sooner or later the Soviets would interfere in Japan’s domestic situation… the only way to save the kokutai would be to negotiate with the United States and Britain as soon as possible, an action that would require the direct intervention of the emperor against the military” (37).

The dropping of the atomic bombs certainly sent a clear message to Japan. Americans had new weapons of war that led to horrific consequences. But the Japanese had also become somewhat used to the constant bombings of their cities and military targets. For many Japanese, the atomic bombs were more of a continuation of these bombings. The atomic bombs were not acts that led to the eventual and unconditional surrender of the emperor. On August 8, the Soviets invaded Manchuria. This came just two days after the bombing of Hiroshima. That combined with the bombings and the Soviet declaration of war against Japan was dangerous. The Japanese knew that they must surrender.

The aftermath

The reasoning for dropping the bombs is debatable. The post-1945 world undoubtedly was forever changed. The use of the bombs led to devastation and deaths. But it also led to a race between states to access and improve the technology used to create these nuclear weapons. The U.S. and Soviet Union, in particular, began building stockpiles of nuclear weapons during the Cold War. In time, other nations such as the U.K., China, France, and India obtained their own nuclear weapons.

The fear and horrific effects of nuclear warfare also led to the creation of numerous anti-nuclear groups. These social movements grew in the 1960s and 1970s. More people demanded a world with fewer threats to both humans and the environment. One of the largest protests in American political history occurred in 1982. About one million people marched in New York City to protest nuclear growth. Marches, protests, activism, and treaties have continued to affect our nuclear age. However, governments have not always been ready and willing to part with their nuclear weapons.

1 Machiavellian is a term used to refer to politicians or heads of state that employ somewhat ruthless practices to achieve their goals. The term comes from the name of the Italian Renaissance author Niccolò Machiavelli, who wrote The Prince as a political guidebook dedicated to Lorenzo de Medici, the ruler of Florence, Italy during the late fifteenth and early sixteenth centuries.

2 Kokutai refers to the idea of sovereignty or national unity in Japan in which the emperor became the supreme authority in terms of the state, national identity, and the military. “The kokutai was a symbolic expression of both the political and the spiritual essence of the emperor system” (Hasegawa, 4). One of the main problems the Japanese had with the terms of the Potsdam Declaration was that it called for unconditional surrender of the emperor,” who symbolized the whole of Japanese culture and the state.