Hiroshima & Nagasaki: the 76th Anniversary of the Atomic Bombings

Learning from the past to build a better future.

It's been 76 years since the U.S. dropped nuclear weapons on the Japanese cities of Hiroshima and Nagasaki. Remembering this collective trauma, we reconsider what we think we know about these events and take lessons for the future.

two men talking
APRIL 27, 1945

Meeting of the Target Selection Committee

A group of military officials and scientists from the Manhattan Project begin meeting over the next few months to discuss targets for the world's first atomic bombs. Crucial target criteria included visibility and expected damage. In later meetings, they also discussed the importance of psychological factors. They wanted to demoralize Japan and also make sure that the first use of nuclear weapons was so spectacular that the international community would recognize the importance of this new weapon. 

Traditional Japanese building

Finalizing the Target List

The committee talked about targeting the Emperor’s palace in Tokyo but ultimately dismissed the idea because Tokyo was already so badly damaged. Despite possessing no real military value, Kyoto was high on the list due to its cultural value to the Japanese. The committee met several more times and then began discussing targets with the War Department. Secretary of War Henry Stimson adamantly opposed targeting Kyoto because he and his wife had visited the city in 1926. It held sentimental value for him. The target list was eventually narrowed down to four cities: Hiroshima, Kokura, Niigata, and Nagasaki.

nuclear explosion
JULY 16, 1945

The world's first atomic bomb is tested

The Trinity Test in southern New Mexico was the first ever detonation of a nuclear weapon. The bomb exploded with the power of 20 kilotons of TNT. The fireball was 600 feet wide; its heat was felt over 100 miles away. 

Fourteen men and one woman in pinstripe suits, ties, and serious faces stand in front of a gothic-revival lancet arch at the University of Chicago.
JULY 17, 1945

Manhattan Project Scientists Petition President Truman Not to Use the Bomb

The day after the world's first test of an atomic weapon, a group of Manhattan Project scientists and technicians created and signed a petition to persuade President Truman not to drop the atomic bomb on Japan. Many of these scientists had witnessed the test, and they understood that the atomic bomb would cause serious destruction and create terrible geopolitical consequences. They were also worried about the moral implications of using the atomic bomb and potentially setting a dangerous precedent.

August 6, 1945

The U.S. Drops "Little Boy" Over Hiroshima

Hiroshima became the first city targeted by an atomic bomb. It was a compact city which meant that the bomb destroyed nearly all of it. The Little Boy bomb was the equivalent of 15,000 tons of TNT and decimated 70% of the buildings in the city. The bombing of Hiroshima killed roughly 135,000 people.

Women and the Bomb

Female survivors of the atomic bombings experienced greater instances of illness and death.  And, they faced harsher societal discrimination after the bombings.

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AUGUST 9, 1945

The Soviet Union Declares War on Japan

In the early hours of August 9, 1945, the Soviet Union declared war on Japan. This was unexpected for the Japanese. Japan had been hoping that the Soviet Union would play the part of mediator when discussing surrender with the United States. But that hope was crushed once the Soviets entered the war in the Pacific Theater. The Japanese were deeply shaken by this development. 

AUGUST 9, 1945

The U.S. drops “Fat Man” Over Nagasaki

The bombing of Nagasaki killed about 80,000 people.  The U.S. government quickly released selected information about the atomic bombings of Japan to the public. Americans initially knew only what was carefully filtered through a public relations effort, and their response was overwhelmingly in favor of the bombings. When polled in August of 1945, 85% of Americans approved of the use of the atomic bomb. For many years the U.S. government kept pictures and videos showing the victims a secret, even censoring the press to do so. It was hard to reconcile the images of burnt and mutilated civilians with America's image of itself as the hero in the story.

bombed out building
August 9, 1945

The Destruction of Urakami Cathedral

One unintended consequence of bombing Nagasaki was destroying the center of Catholicism in Japan. Nagasaki has been the birthplace and capital of Catholicism in Japan since the 16th century. The heart of Catholicism in Nagasaki was the Urakami Cathedral, which was completed in 1925. Twenty years later, it was completely destroyed as Fat Man detonated just hundreds of feet from the Cathedral, killing everyone inside.

A Third Bomb?

It is common belief that two bombs, and two bombs only, were planned to be dropped over Japan. That is not true. In fact, plans for a third bomband many morewere well underway, even after Japan announced its surrender.

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top secret letter
AUGUST 10, 1945

Truman Asserts Control

When Truman learned that a third bomb would be ready in about a week, he ordered that there be no more atomic bombs dropped without his direct approval. When Truman was later asked why he wanted to halt nuclear strikes against Japan, he said that the thought of wiping out another 100,000 people and killing “all those kids” was too horrible.

The President's Sole Authority

Truman's assertion of his authority contributed to the present-day policy of Presidential sole authoritymeaning that only the President, and the President alone, can order the launch of nuclear weapons. 

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AUGUST 10, 1945

Japan Surrenders Conditionally

Japan surrenders on the condition that the Emperor remain the symbolic head of Japan. The U.S. rejects this.

AUGUST 14, 1945

Japan Surrenders Unconditionally

Examining Japan's Surrender

The popular story behind the surrender of Japan was that the bombings of Hiroshima and Nagasaki were so stunning and devastating that they forced Japan to accept defeat. But, there are several competing theories about the impact the bombings had in Japan's decision to surrender. The truth is probably more complex than the simplistic narrative accepted right after the war.

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PRESENT DAY

Survivors Lead Us Toward a Better Future

The survivors of the atomic bombings are known as "Hibakusha." Many of them were just children when the U.S. dropped nuclear weapons on Japan.  Amidst their trauma, many Hibakusha devoted their lives to telling their stories and campaigning against nuclear weapons.

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The U.N. Treaty to Ban the Bomb

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