Atomic Bombs Fall on Hiroshima and Nagasaki, and Japan Surrenders
Two nuclear weapons in three days end the Second World War in the Pacific
Quick facts
- Hiroshima bombed
- 6 August 1945
- Nagasaki bombed
- 9 August 1945
- Surrender announced
- 15 August 1945
- Formal surrender signed
- 2 September 1945, USS Missouri
What happened
By mid-1945, the Office of the Historian notes, American officials "did not debate at length whether to use the atomic bomb against Japan," viewing it as a way to end the Pacific war quickly and avoid the heavier casualties expected from a land invasion. The United States dropped the first atomic bomb on Hiroshima and, three days later, a second on Nagasaki, using the weapons, in the Office's words, "to bring a rapid and conclusive end to the war with Japan." Japan announced its surrender on 15 August 1945, days after the Nagasaki bombing and the Soviet Union's declaration of war and invasion of Manchuria, and signed the formal instrument of surrender aboard the USS Missouri on 2 September 1945.
Why it matters
The atomic bombings remain the only use of nuclear weapons in warfare and ended the Second World War, but they also opened a nuclear age whose weapons and doctrine of deterrence would shape the following decades of global politics, and left Hiroshima and Nagasaki as permanent reference points in debates over the ethics of total war.
How we know
The bombings and Japan's surrender are documented through U.S. military records, Japanese government records of the surrender decision, and the physical historical record preserved at Hiroshima and Nagasaki.
Sources
- Office of the Historian, U.S. Department of State. The Atomic Bomb and the End of World War II · Reputable sourcehistory.state.gov · The domain "history.state.gov" is on our Reputable source registry. · Link is live and its text matches the event's key terms (Jul 2026)
- Office of the Historian, U.S. Department of State. The Atomic Bomb and the End of World War II · Reputable sourcehistory.state.gov · The domain "history.state.gov" is on our Reputable source registry. · Link is live and its text matches the event's key terms (Jul 2026)
See something wrong? . Corrections with a source get fixed fastest.
Related timelines
- World War II → · See the World War II timeline for the Manhattan Project and the broader endgame of the war.