Eighty years after the atomic bombing of Hiroshima, the city remains a powerful symbol of both devastation and resilience. While the attack played a decisive role in ending World War II, its effects on survivors, international affairs and global nuclear policy are still felt today.

This article explores what happened before, during and after the bombing.

What happened?

On August 6, 1945, the United States dropped the world’s first atomic bomb – nicknamed Little Boy – on the Japanese city Hiroshima. Approximately 140,000 people died by the end of that year, while another 210,000 survived, many of whom faced long-term health consequences from intense radiation exposure.

Three days later, a second, more powerful counterpart – Fat Man – was dropped on Nagasaki.

The devastation led to Japan’s surrender. After the defeat of the Axis forces in Europe earlier that year, Japan continued fighting against the Allied Powers, led by the United States, United Kingdom, China and the Soviet Union. On August 10, a day after the destruction of Nagasaki, Japan offered a conditional surrender, which the Allies rejected. On August 14, Japan accepted the terms of unconditional surrender.

The following day marked Victory over Japan, but the formal surrender did not take place until September 2, aboard the USS Missouri, officially ending World War II.

Was it justified?

The US government’s decision to use atomic bombs remains widely disputed.

However, the critics argue that Japan was already on the brink of surrender and that the bombings were unnecessary. The second strike on Nagasaki has been highly criticised for being rushed, as they were carried out before Japan could fully process and respond to the destruction in Hiroshima.

In his memoir “I Was There,” Admiral William Leahy, chief of staff to the president, wrote: “It is my opinion that the use of this barbarous weapon at Hiroshima and Nagasaki was of no material assistance in our war against Japan. The Japanese were already defeated and ready to surrender.”

Aftermath and reconstruction

Despite the destruction, Hiroshima’s reconstruction began almost immediately. Within a week, the city had partially restored its streetcar operations, water systems and light sources.

However, full-scale reconstruction did not begin until after Japan’s official surrender. At first, Hiroshima faced many rebuilding challenges, including difficulties with finances, human resources and materials. To address these challenges, the government passed the Hiroshima Peace Memorial City Construction Law in 1949, offering financial support, land and repurposing former military property for reconstruction.

One major debate among Hiroshima citizens was whether to preserve the ruins or erase reminders of war. Eventually, the city embraced a dual identity: a rebuilt urban centre and a living peace memorial.

At the heart of Hiroshima’s Peace Memorial Park stands the Genbaku Dome (A-Bomb Dome), the only building near the blast’s hypocenter to partially survive. As the explosion was almost directly overhead, the building was not subject to the blast wave and able to retain its shape.

Originally the Hiroshima Prefectural Industrial Promotion Hall (built in 1914), it remains preserved as a UNESCO World Heritage Site and a haunting reminder of the horrors of nuclear war.

How many survivors are still alive?

The survivors of Hiroshima and Nagasaki are known as hibakusha, and those who suffered the effects of both bombings are known as nijū hibakusha.

Hibakushas suffered long-term health effects, especially leukemia, cancer and the consequences of psychological trauma. They were also subject to discrimination limiting their marriage and employment prospects.

As of 2025, fewer than 100,000 hibakushas are still alive.

Nuclear proliferation today

Despite international calls for disarmament, nuclear weapons remain a key component of global military strategy.

The bombings of Hiroshima and Nagasaki sparked global fear, leading to the doctrine of Mutually Assured Destruction (MAD), a political and military assumption that the full use of nuclear weapons would result in the annihilation of all parties involved.

While Hiroshima and Nagasaki have since become symbols of peace and led anti-nuclear movements, nuclear proliferation has persisted. During the Cold War, despite the United Nation’s call for disarmament in 1946, the Soviet Union, United Kingdom, France and China developed their own nuclear weapons.

The most significant global treaty against nuclear weapons is the Non-Proliferation Treaty (NPT), signed by 191 countries, including five of the nine nuclear-armed countries: the United States, Russia, China, France and the United Kingdom. The agreement entered into force in 1970.

However, India, Pakistan, Israel and North Korea, have not joined the treaty. Iran, though a signatory, has repeatedly breached transparency obligations and continues to resist full cooperation with the International Atomic Energy Agency (IAEA).

Today, an estimated 12,000 nuclear warheads are held by nine countries. Some, like China, are expanding their stockpiles rapidly, reportedly adding over 100 warheads annually. Modern nuclear weapons are also far more powerful than those used in 1945, with a potential to kill millions.