Unit 3: The Decision to Drop the Bomb

“That was not any decision you had to worry about.”

President Harry S. Truman

While Americans and Japanese alike expected the war to end after a bloody invasion of Japan, the U.S. government was readying a secret weapon that would dramatically affect the war’s outcome: the atomic bomb. In the spring and summer of 1945, American leaders had to decide whether to use this new weapon without warning against Japanese cities.

However, British Prime Minister Winston Churchill said, “The decision whether or not to use the atomic bomb…was never even an issue.” Upon becoming President in April 1945, Harry Truman inherited a costly bomb project that had always aimed at producing a military weapon. Furthermore, he was faced with the prospect of an invasion and was told that the bomb would help impress the Soviet Union. He, therefore, saw no reason to avoid using the bomb. Alternatives for ending the Pacific war other than an invasion of atomic bombing were available but are more evident in hindsight than they were at the time.

“That was not any decision you had to worry about.”

President Harry S. Truman

While Americans and Japanese alike expected the war to end only after a bloody invasion of Japan, the U.S. government was readying a secret weapon that would dramatically affect the war’s outcome: the atomic bomb. In the spring and summer of 1945, American leaders had to decide whether to use this new weapon against Japanese cities.

However, British Prime Minister Winston Churchill said, “The decision whether or not to use the atomic bomb…was never even an issue.” Upon becoming President in April 1945, Harry Truman inherited an expensive bomb project that had always aimed at producing a military weapon. Truman saw the bomb as a way to end the war and save lives by avoiding a costly invasion of Japan. He wanted, he said, to prevent casualties on the scale of “an Okinawa from one end of Japan to the other.”

Rising from humble origins in the Kansas City area, Truman was a veteran of World War I and a successful Missouri politician. He achieved prominence in the Second World War as a U.S. Senator and Chairman of the so-called Truman Committee, which acted as a watchdog over the vast industrial and military buildup during the war. In the fall of 1944, he was elected as Roosevelt’s third Vice-President.

Truman was aware of the existence of the Manhattan Project while a Senator but respected the Administration’s request that he not inquire into its nature. As president, he was responsible for using the atomic bomb. After the war, he claimed that he never had moral qualms about the bombings, but his diaries and letters indicate that this was not entirely the case. He was reelected in 1948 and was noteworthy for his role in the early Cold War, the Marshall Plan, the Berlin airlift, and the Korean War.

HENRY L. STIMSON (1867-1950)

Born into a privileged northeastern family, Stimson was a prominent figure in the American political establishment for over four decades. He had been Secretary of War for President William Howard Taft, Governor-General of the Philippines for President Calvin Coolidge, and Secretary of State for President Herbert Hoover. Although Stimson was a lifelong Republican, President Roosevelt asked him to take over as Secretary of War in 1940 because of the urgent military buildup that began after Nazi victories in Europe.

Stimson was drawn into atomic-bomb decision-making in October 1941 when Roosevelt prioritized the program. During the war, he remained a key policy adviser on nuclear energy. Despite poor health and advanced age, Stimson continued to play the same role under President Truman, although he was increasingly displaced by Truman’s choice for Secretary of State, James Byrnes. Stimson went into a well-deserved retirement shortly after the surrender of Japan.

President Truman “was like a little boy on a sled. He never had the opportunity to say, ‘We will drop the bomb.’ All he could do was say ‘no.'”

General Leslie Groves

President Truman came into office with no knowledge of the atomic bomb because Roosevelt had never revealed to him the secret at the heart of the Manhattan Project. Shortly after Truman’s swearing-in on April 12, Secretary of War Henry Stimson mentioned it to him briefly. On April 25, Stimson gave him a more extensive briefing, accompanied by General Groves.

The president had inherited a project that had always aimed at making a usable weapon. He never saw a compelling reason to question the assumption in the following months. As a result, Truman’s role in the “decision to drop the bomb” was confined mainly to verbally confirming proposals by his advisers.

Senator Harry S. Truman (1884-1972): A World War I veteran and Missouri farmer and politician, Truman achieved prominence in the U.S. Senate as chairman of the powerful Truman Committee, which watched over the U.S. industrial and military buildup during World War II. As president, he was responsible for using the atomic bomb.

Secretary of War Henry L. Stimson (1867-1950): A prominent statesman for over 40 years, Stimson served as Secretary of War for William Howard Taft, Governor-General of the Philippines for Calvin Coolidge, and Secretary of State for Herbert Hoover. Although Stimson was a lifelong Republican, he became Roosevelt’s Secretary of War in 1940 and a key policy advisor on the atomic bomb.

On April 5, 1945, one week before Roosevelt’s death, Japanese Prime Minister Koiso, and his Cabinet resigned because of the increasingly disastrous course of the war. It was the second such resignation in less than a year. Even the military-dominated Japanese political establishment was beginning to realize that a way had to be found to negotiate an end to the war. However, the Allied demand for “unconditional surrender” was regarded as intolerable.

Emperor Hirohito approved the appointment of the aged Admiral Kantaro Suzuki as the new Prime Minister. But Suzuki’s government was hobbled by severe tensions between civilian politicians interested in peace and die-hard military leaders who wished to fight a last battle in Japan. Surrender could not be openly discussed, nor could direct negotiations with the United States be undertaken because hawkish Army generals dominated the government. As a result, opportunities to end the war early were greatly limited.

On April 5, 1945, one week before Roosevelt’s death, Japanese Prime Minister Kuniaki Koiso, and his Cabinet resigned because of the increasingly disastrous course of the war–the second such resignation in less than a year. A peace faction in the military-dominated Japanese government had begun to realize that a way had to be found to negotiate an end to the war. However, the Allied demand for “unconditional surrender” was regarded as intolerable.

Emperor Hirohito approved the appointment of the aged Admiral Kantaro Suzuki as the new Prime Minister. But Suzuki’s government was hobbled by severe tensions between the peace faction and militarists who vowed to fight to the bitter end. As a result, direct negotiations with the United States could not be undertaken, and Japan lost an opportunity to try to end the war early.

Throughout the Pacific War, the Soviet Union and Japan remained at peace, although they were allied with opposite sides in the European war. In the fall of 1944, the growing desperation of the Japanese government drove it to approach Joseph Stalin’s communist regime for help in fending off defeat. After the appointment of the Suzuki cabinet in April 1945, these initiatives were renewed.

Two key civilian politicians–Marquis Kido, the Emperor’s closest adviser, and Shigenori Togo, the new Foreign Minister–hoped to use the renewed approach to Moscow to negotiate some conditional surrender with the Allies. But they had to conceal their true intentions from the die-hard militarists who wished to fight on. As a result, the initiative remained weak and indecisive.

EMPEROR HIROHITO (1901-1989)

Crowned as the Showa (“Enlightened Peace”) Emperor in 1926, Hirohito played a controversial role in World War II. A retiring and bookish man traditionally restricted from exercising much influence over the government, he was simultaneously worshipped as a god by the Japanese people and military. He became a symbol of Japanese aggression and barbarism to the outside world, yet he occasionally expressed his reservations to the military leadership about the course of the war. He nonetheless showed much enthusiasm for the armed forces and their conquests.

In the spring of 1945, Hirohito was aware that the war was lost and gave tentative encouragement to the peace feelers of Marquis Kido and Foreign Minister Togo. But he failed to take more decisive action until August, when the atomic bombs were dropped, and the Soviets declared war. Following the surrender, the Allies allowed Hirohito to remain on the throne. He presided over the Renaissance of modern Japan.

->->se, if warned, might try to shoot down the bomber or move prisoners of war into the target area because the demonstration bomb might fail to explode.

Others who knew about the atomic bomb also considered ways to demonstrate it. For example, Manhattan Project physicist Edward Teller proposed exploding the first bomb high over Tokyo Bay at night, without warning, to shock the Japanese leaders. But before the first test, the scientists had generally underestimated the power of the bomb, and it was not clear that any non-lethal demonstration would sufficiently impress the Japanese.

PEACE THROUGH MOSCOW?

The Soviet Union and Japan had remained at peace, although they were allied with opposite sides in the European war. In the fall of 1944, growing desperation drove the Japanese government to approach Joseph Stalin’s communist regime for help in fending off defeat. These initiatives were renewed after the Suzuki cabinet was appointed in April 1945.

Two key civilian politicians -Marquis Kido, the Emperor’s closest adviser, and Shigenori Togo, the new Foreign Minister-hoped to use this initiative to negotiate a conditional surrender with the Allies. But they had to conceal this intention from the militarists who vowed to fight until the Allies gave Japan more concession. As a result, the Moscow initiative remained weak and indecisive.

Emperor Hirohito (1901-1989): A retiring and bookish man, the Emperor had traditionally been portrayed as a “living god” who exercised little absolute authority over state affairs. The reality was more complex. While he opposed war with the United States and Britain before 1941, he did not discourage Japanese expansionist policies in Asia. Although he tentatively encouraged the Moscow peace initiative in 1945, he also listened to military advisors who argued that one final victory would force Allied leaders to offer improved peace terms. He failed to take decisive action until the atomic bombs had been dropped and the Soviets had declared war.

Throughout the discussions of the Interim and Target Committees, the escalation of bombing attacks on civilians in World War II was an important precedent and context. When Oppenheimer suggested on May 31 that several atomic attacks be carried out on the same day to shock the Japanese, Groves opposed the idea because “the effect would not be sufficiently distinct from our regular air force [bombing] program” At that time, the firebombing of Japanese cities had already killed around two hundred thousand people

The yield of the first atomic bombs was also estimated at only one-tenth to one-half of what they turned out to be, and until after the July nuclear test, no one had a clear impression of what the heat and radiation effects would be like. As a result, many of those knowledgeable about the bomb did not see it as being drastically different than conventional strategic bombing, nor did they expect that the bomb would automatically end the war.

At the war’s end, little remained standing in the firebombed sections of Tokyo.

“SUCH ATTACKS ON JAPAN COULD NOT BE JUSTIFIED”

Not everyone inside the small group privy to the atomic secret agreed that the bomb should be used without warning on Japanese cities. The most robust protest base was in the Manhattan Project laboratory at the University of Chicago. Leo Szilard and other scientists there felt that the bomb project had primarily responded to a threat from Germany. Attacking Japan, they felt, would not be fair without an opportunity being given to surrender first. They were equally concerned that using the bomb without warning the Japanese or telling the Soviets would increase the chances of an uncontrolled nuclear arms race with the USSR after the war.

The Chicago group tried writing a report, sending petitions to President Truman, and approaching Truman’s adviser and choice for Secretary of State, “Jimmy” Byrnes. The president never received the petitions, and all the scientists’ initiatives were frustrated because of the opposition of Byrnes, Groves, Oppenheimer, and other policymakers and scientists in control of the nuclear program.

Many decision-makers knowledgeable about the bomb did not consider it drastically different from conventional strategic bombing, which had already killed hundreds of thousands of civilians worldwide. Nor was there any guarantee that the bomb would automatically end the war.

When Oppenheimer suggested on May 31 that several atomic attacks be carried out on the same day to shock the Japanese, Groves opposed the idea because “the effect would not be sufficiently distinct from our regular air force [bombing] program.” At that time, the firebombing of Japan had already devastated many cities. The explosive power of the first atomic bombs was also estimated at only 1/10th to 1/2 of what it turned out to be, and no one had a clear impression of the heat and radiation effects.

Opposition to dropping the atomic bomb on Japan without warning also came from inside the military establishment. The most famous cases are those of Admiral Leahy and General (later President) Eisenhower. Leahy said in 1950 that he had denounced the bombing as adopting “ethical standards common to barbarians in the dark ages,” but 1945 documents only suggest that he was skeptical that the atomic bomb would ever work. Eisenhower claimed in 1948, and in his later memoirs, to have opposed the use of the bomb in conversations with President Truman at the Potsdam Conference in July 1945. But corroborating evidence for these assertions is weak.

We do know, however, that top civilian officials in the military departments, including Undersecretary of the Navy Ralph Bard and Assistant Secretary for War John McCloy, opposed the policy of use without warning.

Leo Szilard and other Manhattan Project scientists there felt that the bomb project had primarily responded to a threat from Germany. They felt that attacking Japan without first providing a warning and an opportunity to surrender would weaken “our moral position…in the eyes of the world.” They were equally concerned that using the bomb without telling the Soviets first would increase the chances of an uncontrolled nuclear arms race after the war.

The Chicago group wrote a report, sent petitions to President Truman, and approached Truman’s adviser and choice for Secretary of State, James Byrnes. But the president did not receive the petitions before the bomb was used, and Byrnes, Groves, Oppenheimer, and others obstructed all the scientists’ initiatives.