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.

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.

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.

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.

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.
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.
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.
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.

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.

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