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:

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.