Hiroshima Day 2025: Know All About the Decision to Drop the Atomic Bomb on Hiroshima and Nagasaki

Hiroshima Day is observed every year on August 6 to remember one of the most tragic days in human history, which is the atomic bombing of Hiroshima in 1945. On this day, during the final stages of World War II, the U.S. had dropped an atomic bomb named “Little Boy” from the B-29 bomber “Enola Gay” over the city of Hiroshima on August 6, 1945 and another atomic bomb was dropped on Nagasaki on August 9, 1945.

In 2025, 6 August will be marked as the Hiroshima Day and it will be its 80th anniversary and this day should be recognised as the day of remembrance for the atomic bombing of Hiroshima in 1945 and in recognition of victims of nuclear-as-a means to reiterate the requirement of global nuclear disarmament.

On August 6, 1945, an atomic bomb was dropped on #hiroshima. Later, the city was designated as a #hiroshimapeacememorial, and the reconstruction progressed. This movie shows the progress of Hiroshima's reconstruction 16 years after the bombing.
Full movie👉https://t.co/uBDZlRhbzS pic.twitter.com/7SPmPyrkDT

— MOFA of Japan (@MofaJapan_en) August 6, 2024

The impact after the dropping of an atomic bomb was so catastrophic. Nearly 130,000 people died instantly, and by the end of the year, the death toll rose to approximately 140,000, due to radiation-related illnesses and injuries. The city was destroyed in very large numbers, the whole biodiversity was affected after the dropped of an atomic bomb on Hiroshima and Nagasaki. Those who were able to survive anyway, these survivors, known as “hibakusha”, and those survivors who were safe, have been able to carry the burden of severe health issues, trauma, and societal discrimination for decades.

Hiroshima Day is now globally observed as a solemn occasion to honour the victims and remind the world of the devastating consequences of nuclear warfare. Vigils, peace memorials, and symbolic ceremonies—such as floating lanterns—take place in various countries, always echoing the same urgent message: never again.

On the 80th Anniversary of the Atomic Bombing of Hiroshima, Secretary-General Izumi Nakamitsu delivered the message  to the Hiroshima Peace Memorial,

"Eighty years ago, the world changed forever.

In a single moment, Hiroshima was engulfed in flames. Tens of thousands of lives were lost. A city was reduced to ruins. And humanity crossed a threshold from which there could be no return.

On this 80th anniversary, we remember those who perished. We stand with the families who carry their memory.

And we honour the brave hibakusha — the survivors — whose voices have become a moral force for peace. While their numbers grow smaller each year, their testimony — and their eternal message of peace — will never leave us.

In the aftermath of the atomic bombing, many believed Hiroshima would never recover and that nothing would grow again. But the people of this city proved otherwise.  

You, the people of Hiroshima, didn’t just rebuild a city. You rebuilt hope. You nurtured a vision of a world without nuclear weapons. And you shared that vision with the world.

In May, saplings grown from seeds of trees that survived the atomic bombing were planted at United Nations Headquarters in New York. They are more than symbols of survival. They are living testaments to the strength of the human spirit — and of our shared duty to protect future generations from the horrors of nuclear annihilation.

This year also marks the 80th anniversary of the United Nations, and we are reminded why the UN was created: to prevent war, to uphold human dignity, and to ensure the tragedies of the past are never repeated.

Yet, today the risk of nuclear conflict is growing. Trust is eroding. Geopolitical divisions are widening. And the very weapons that brought such devastation to Hiroshima and Nagasaki are once again being treated as tools of coercion.

Yet, there are signs of hope.

Last year, the Japanese organization Nihon Hidankyo — which represents the survivors of the Nagasaki and Hiroshima bombings — was awarded the 2024 Nobel Peace Prize for its tireless work in raising awareness about this critical issue.

And in the Pact for the Future, adopted last year, countries re-committed to a world free of nuclear weapons.

But commitments must lead to real change by strengthening the global disarmament regime — in particular, the Treaty on Non-Proliferation of Nuclear Weapons, complemented by the momentum created by the Treaty on the Prohibition of Nuclear Weapons.

Countries must draw strength from the resilience of Hiroshima and from the wisdom of the hibakusha. 

Let’s work to eradicate the threat of nuclear weapons by eradicating the weapons themselves.

And let’s keep our pledge to the hibakusha, and ensure that their testimony and message of peace is carried forward. Remembering the past is about protecting and building peace today — and in the future." 

Quick Comparison Table: Hiroshima vs. Nagasaki Bombings

What are the Historical Background of the Decision to Drop the Atomic Bomb on Hiroshima and Nagasaki?

The decision to drop the atomic bombs on Hiroshima and Nagasaki was part of the U.S. and this strategy was only to swiftly end World War II. On the morning of August 6, 1945, at 8:15 a.m., the Enola Gay dropped the atomic bomb over the city, making Hiroshima the first city in history to experience the power of nuclear warfare.

The immediate effects were devastating, and within minutes, there was so much destruction seen in Hiroshima. In the following days and months, more victims succumbed to burns, radiation sickness, and injuries. The environment suffered irreversible damage, and future generations of survivors faced long-term health complications.

Just three days later, on August 9, the U.S. dropped another atomic bomb, this time on Nagasaki, leading to further massive loss of life. These back-to-back bombings played a significant role in Japan’s decision to surrender, effectively bringing World War II to an end on August 15, 1945.

Why were the reasons behind the decision to drop the Atomic Bomb on Hiroshima and Nagasaki made?

The Decision Behind the Bombings: Why It Happened

The road to Hiroshima began years before the war formally started. Japan’s expansionist ambitions led to invasions in Asia, especially Manchuria in 1931 and much of China by 1937. The U.S. and other powers objected, but took little action initially. As Japan’s aggressions continued—particularly toward resource-rich Southeast Asia—the U.S. imposed economic sanctions, including freezing Japanese assets and cutting off oil and raw materials.

Japan viewed these moves as acts of provocation and, anticipating conflict, launched a surprise attack on Pearl Harbour on December 7, 1941. This prompted the U.S. to officially enter World War II.

The war in the Pacific was long and brutal. The Battle of Okinawa, one of the last major confrontations, took the lives of over 100,000 people on both sides. Faced with the possibility of a costly invasion of Japan, President Harry Truman, who had taken office after Franklin D. Roosevelt’s death in April 1945, was presented with another option: use the newly developed atomic bomb.

This atomic bomb was developed under the Manhattan Project. This secret weapon had just been tested successfully in New Mexico. On July 26, 1945, Truman issued the Potsdam Declaration, calling for Japan’s unconditional surrender or face "prompt and utter destruction." Japan did not respond.

On August 6, the first atomic bomb was dropped on Hiroshima. On August 9, a second bomb—“Fat Man”—was dropped on Nagasaki, killing around 39,000 instantly and injuring thousands more. The dual bombings forced Japan to surrender, ending a long and deadly global conflict.

Why Hiroshima Day Matters Today?

Hiroshima Day is more than a remembrance—it is a global call for peace and nuclear disarmament. In a world where nuclear weapons still exist, the memory of Hiroshima and Nagasaki serves as a stark warning of what is at stake. The day urges humanity to pursue peaceful conflict resolution, promote global dialogue, and ensure that such weapons are never used again.

Conclusion

Hiroshima Day is not just a historical reflection—it’s a moral reminder. It teaches us the fragility of peace, the destructive capacity of human invention, and the responsibility we carry as global citizens to advocate for a safer, nuclear-free future.