August 1942
Manhattan Project established in US
The United States sets up the Manhattan Project to develop the first nuclear weapon
16 July 1945
US conducts first ever nuclear test
The United States tested a 15-20 kilotonne nuclear weapon south of Socorro, New Mexico. Radiation levels around the site remain 10 times as high as natural background radiation. Photo: https://www.atomicheritage.org/history/trinity-test-1945
6 August 1945
US drops atomic bomb on Hiroshima
The United States detonates a uranium bomb over Hiroshima, Japan killing more than 140,000 people within months. Many more later die from radiation-related illnesses.
9 August 1945
A second bomb is dropped on Nagasaki
The United States explodes a plutonium bomb over Nagasaki. An estimated 74,000 people die by the end of 1945.
24 January 1946
UN calls for elimination of atomic weapons
In its first resolution, the UN General Assembly calls for the complete elimination of nuclear weapons and sets up a commission to address nuclear weapons.
29 August 1949
Soviet Union tests its first nuclear bomb
The Soviet Union explodes a nuclear weapon code-named “First Lightning” in Semipalatinsk, Kazakhstan, becoming the second country to develop and successfully test a nuclear device.
3 October 1952
UK tests nuclear weapon in Australia
The United Kingdom conducts its first nuclear test at Montebello Islands off the coast of Western Australia. It later conducts a series of tests at Maralinga and Emu Fields in South Australia.
1 November 1952
US tests the first hydrogen bomb
The United States detonates the first hydrogen bomb at Enewetak Atoll in the Marshall Islands. It is 500 times more powerful than the Nagasaki bomb.
1 March 1954
US conducts massive “Bravo” test
The United States detonates a 17-megaton hydrogen bomb, “Bravo”, at Bikini Atoll in the Pacific Ocean, contaminating a Japanese fishing boat, Lucky Dragon, and residents of Rongelap and Utirik.
9 July 1955
Russell–Einstein manifesto issued
Bertrand Russell, Albert Einstein and other leading scientists issue a manifesto warning of the dangers of nuclear war and urging all governments to resolve disputes peacefully.
17 February 1958
UK disarmament campaign formed
The Campaign for Nuclear Disarmament in the UK holds its first meeting. Its iconic emblem becomes one of the most widely recognized symbols in the world.
1 December 1959
Nuclear tests banned in Antarctica
The Antarctic Treaty opens for signature. It establishes that “any nuclear explosion in Antarctica and the disposal there of radioactive waste material shall be prohibited”.
13 February 1960
France tests its first nuclear weapon
France explodes its first atomic bomb in the Sahara desert. It has a yield of 60–70 kilotons. It later moves its nuclear tests to the South Pacific. These continue up until 1996.
30 October 1961
Largest ever bomb test conducted
The Soviet Union explodes the most powerful bomb ever: a 58-megaton atmospheric nuclear weapon, nicknamed the “Tsar Bomba”, over Novaya Zemlya off northern Russia.
16–29 October 1962
Cuban Missile Crisis occurs
A tense stand-off begins when the United States discovers Soviet missiles in Cuba. The United States blockades Cuba for 13 days. The crisis brings the United States and the Soviet Union to the brink of nuclear war.
5 August 1963
Partial Test Ban Treaty opens for signature
A treaty banning nuclear testing in the atmosphere, outer space and underwater is signed in Moscow, following large demonstrations in Europe and America against nuclear testing.
16 October 1964
China conducts its first nuclear test
China explodes its first atomic bomb at the Lop Nor testing site in Xinjiang Province. In total, China conducts 23 atmospheric tests and 22 underground tests at the site.
14 February 1967
Latin America becomes nuclear-free
A treaty prohibiting nuclear weapons in Latin America, the Treaty of Tlatelolco, is signed at Mexico City. Parties agree not to manufacture, test or acquire nuclear weapons.
1 July 1968
Non-Proliferation Treaty opens for signature
Under the Nuclear Non-Proliferation Treaty, non-nuclear-weapon states agree never to acquire nuclear weapons, and the nuclear-weapon states make a legal undertaking to disarm.
18 May 1974
India conducts first nuclear test
India conducts an underground nuclear test at Pokharan in the Rajasthen desert, codenamed the “Smiling Buddha”.
22 September 1979
Nuclear explosion in Indian Ocean
A nuclear test explosion occurs over the South Indian Ocean off the Cape of Good Hope. It is thought to have been conducted by South Africa with the assistance of Israel.
12 June 1982
A million people rally for disarmament
One million people gather in New York City’s Central Park in support of the nuclear freeze movement. It is the largest anti-war demonstration in history.
10 July 1985
Rainbow Warrior ship destroyed
The Greenpeace ship Rainbow Warrior is destroyed in New Zealand on its way to the Murorua Atoll to protest French nuclear tests. New Zealand later enacts nuclear-free legislation.
6 August 1985
South Pacific becomes nuclear-free
The South Pacific Nuclear Free Zone Treaty is signed at Rarotonga in the Cook Islands. The treaty prohibits the manufacturing, stationing or testing of nuclear weapons within the area.
10 December 1985
Anti-nuclear doctors win Nobel
The International Physicians for the Prevention of Nuclear War receives the Nobel Peace Prize for its efforts to bridge the cold war divide by focusing on the human costs of nuclear war.
30 September 1986
Israel’s nuclear programme revealed
The Sunday Times publishes information supplied by Israeli nuclear technician Mordechai Vanunu, which leads experts to conclude that Israel may have up to 200 nuclear weapons.
11–12 October 1986
US and Soviet leaders discuss abolition
US President Ronald Reagan and Soviet President Mikhail Gorbachev meet at Reykjavik, Iceland, where they seriously discuss the possibility of achieving nuclear abolition.
8 December 1987
Intermediate-range missiles banned
The Soviet Union and United States sign the Intermediate-Range Nuclear Forces Treaty to eliminate all land-based missiles held by the two states with ranges between 300 and 3,400 miles.
10 July 1991
South Africa joins Non-Proliferation Treaty
South Africa accedes to the Nuclear Non-Proliferation Treaty. The government claims to have made six nuclear weapons and to have dismantled them all.
15 December 1995
Southeast Asia becomes nuclear-free
The nations of Southeast Asia create a nuclear-weapon-free zone stretching from Burma in the west, the Philippines in the east, Laos and Vietnam in the north, and Indonesia in the south.
11 April 1996
Africa becomes a nuclear-free zone
Officials from 43 African nations sign the Treaty of Pelindaba in Egypt establishing an African nuclear-weapon-free zone and pledging not to build, test, or stockpile nuclear weapons.
1 June 1996
Ukraine becomes a nuclear-free state
Ukraine becomes a nuclear-weapon-free state after transferring the last inherited Soviet nuclear warhead to Russia for destruction. Its president calls on other nations to follow its path.
8 July 1996
ICJ Rules on Nuclear Weapons
The International Court of Justice hands down an advisory opinion in which it found that the threat or use of nuclear weapons would generally be contrary to international law, but the court could not conclude if the use of nuclear weapons would be lawful or unlawful in the case of “extreme circumstance of self-defence, in which the very survival of a state would be at stake”.
24 September 1996
Total nuclear test ban opens for signature
The Comprehensive Test Ban Treaty opens for signature at the United Nations. China, France, the United Kingdom, Russia and the United States all sign the treaty. India says it will not sign the treaty.
27 November 1996
Belarus removes its last nuclear missile
Belarus turns its last nuclear missile over to Russia for destruction. It joins Ukraine and Kazakhstan as former Soviet republics that have given up all their nuclear arms.
May 1998
India and Pakistan conduct nuclear tests
India conducts three underground nuclear tests, its first in 24 years. One is a thermonuclear weapon. Later in May, Pakistan tests six nuclear weapons in response to India’s tests.
9 October 2006
North Korea conducts nuclear test
The North Korean government announces that it has successfully conducted a nuclear test.