The first nuclear weapon was used in 1945. As the Second World War was coming to an end, the United States dropped this brand new weapon on the cities of Hiroshima and Nagasaki in Japan. Today there are 13,000 nuclear weapons in the world, each with the possibility to devastate our planet. Many thought the end of the Cold War would mean an end to nuclear weapons but today we see a dangerous escalation of the nuclear arms race.

Below we chart the timeline of the history of nuclear weapons. Let’s hope an end date can be added soon.

The US’ Manhattan Project builds and tests the first atomic bombs. The new weapons are used on Hiroshima, then Nagasaki. The Second World War ends, as we see the beginning of the Cold War. The Soviet Union tests its first atomic bomb in 1949.

Key dates
July 1945 The United States conducts the world’s first atomic bomb test, called ‘Trinity’, at Alamogordo, New Mexico.

August 1945 The United States drops atomic bombs on Hiroshima and Nagasaki.

August 1949 The Soviet Union tests its first atomic bomb.

This decade sees the UK first testing an atomic bomb and the formation of the Campaign for Nuclear Disarmament.

Key dates
1949 The North Atlantic Treaty Organisation (NATO) is formed.

March 1950 The World Peace Council publishes the Stockholm Appeal calling for an absolute ban on nuclear weapons.

October 1952 First British atomic bomb test off the coast of Australia.

January 1954 The world’s first nuclear-powered submarine, the USS Nautilus, is launched.

March 1954 First US hydrogen bomb test.

March 1954 A Japanese fishing boat, the Daigo Fukuryu Maru, is exposed to radioactive fallout from an American hydrogen bomb test at Bikini Atoll in the Pacific; one crew member later dies as a result of exposure to radiation.

May 1955 Warsaw Treaty Organisation (Warsaw Pact) is formed.

April 1956 The Soviet Union announces it has a hydrogen bomb.

May 1957 First British hydrogen bomb test in Australia.

September 1957 The United States conducts its first underground nuclear test.

October 1957 Major fire at the Windscale (now Sellafield) nuclear site in Cumbria results in radioactive discharges.

February 1958 CND is formed.

February 1958 US supplies Thor atomic missiles to the UK.

Easter 1958 The first march to Aldermaston (where Britain’s nuclear bombs are made) takes place.

France and China become nuclear powers. The Cuban Missile Crisis brings the world to the brink of a nuclear war, but in more positive news the nuclear Non-Proliferation Treaty (in which the nuclear powers promise to bring about complete nuclear disarmament and non-nuclear powers agree not to acquire the weapon) is agreed. The decade sees a massive increase in political protests across the world.

Key dates
February 1960 France conducts its first nuclear test in Algeria.

March 1961 The first US nuclear submarine arrives at Holy Loch, in Scotland.

Easter 1962 100,000 attend rally at the end of an Aldermaston march.

October 1962 Cuban missile crisis – a month-long confrontation between the US and Soviet Union, which many believe to be the closes the world has come to a nuclear war.

December 1962 UK government announces purchase of Polaris missile from the US.

October 1963 Partial Test Ban Treaty – which prohibits nuclear tests anywhere but underground – enters into force.

October 1964 China conducts its first atomic bomb test.

February 1967 Treaty of Tlatelolco is signed, prohibiting nuclear weapons in Latin America and the Caribbean.

October 1967 The Outer Space Treaty enters into force, which bans putting nuclear weapons in space.

July 1968 The nuclear Non-Proliferation Treaty is signed. Nuclear-armed states agree to work towards disarmament, while non-nuclear states agree not to acquire nuclear weapons.

The decade opens on a positive note as further arms control treaties are agreed, but ends with a tragic incident at Three Mile Island nuclear energy plant in Pennsylvania, where the plant approached meltdown in a near catastrophic accident.

Key dates
March 1970 The nuclear Non-Proliferation Treaty  enters into force.

May 1972 The US and the Soviet Union conclude the Anti-Ballistic Missile (ABM) Treaty and the Strategic Arms Limitation Treaty (SALT I).

September 1972 Labour Party conference votes for unilateral nuclear disarmament.

June 1973 The United States and the Soviet Union sign the Agreement on the Prevention of Nuclear War.

May 1974 India conducts its first nuclear tests underground.

October 1977 Liberal Party conference votes against the development of nuclear power.

May 1978 The United Nations General Assembly holds its first special session on disarmament.

March 1979 A severe accident occurs at the Three Mile Island nuclear power plant in Pennsylvania, the most significant in the US’ history.

June 1979 The United States and the Soviet Union sign SALT II.

December 1979 NATO announces that 572 US cruise and Pershing missiles will be based in Europe (including Britain).

With the Cold War at its height, the number of nuclear weapons in the world reaches its highest ever levels. It is revealed that Israel may have up to 200 nuclear weapons stockpiled. Anti-nuclear demonstrations regularly take place in the UK, with many peace camps being formed, including the famous women’s peace camp at Greenham Common.

Key dates
June 1980 The UK government announces Greenham Common in Berkshire and Molesworth in North Hamptonshire as bases for cruise missiles. It also announces its intention to develop Trident, a new nuclear weapons system.

November 1980 Manchester is the first local authority in the UK to declare itself a nuclear-free zone.

1981 The Trades Union Congress (TUC) votes in favour of unilateral nuclear disarmament.

September 1981 Women’s Peace Camp set up at Greenham Common. Huge anti-nuclear protests across Europe.

June 1982 250,000 protest against nuclear weapons in London, while 30,000 women surround Greenham Common. Home Office cancels civil defence exercise ‘Hard Rock’ as local authorities refuse to take part. Faslane Peace Camp is formed.

March 1983 United States President Ronald Reagan announces the Strategic Defence Initiative (SDI) programme. Nicknamed ‘Star Wars’, this was the first ever plans for a missile defence system.

April 1983 CND organises 14 mile human chain linking Greenham Common, Aldermaston and Burghfield.

October 1983 250,000 protest against nuclear weapons in London.

December 1983 First cruise missiles arrives at Greenham Common.

August 1985 The Treaty of Rarotonga is signed, declaring the South Pacific nuclear-free.

April 1986 A disastrous accident occurs at the Chernobyl nuclear power plant in Ukraine.

1989 The fall of the Berlin Wall, signifying the end of the Cold War.

The hope of a nuclear-free world post the Cold War gets a boost when Ukraine, Kazakhstan and Belarus choose to return their nuclear arsenals, inherited from the former Soviet Union, to Russia. But by the end of the decade, two further countries – India and Pakistan – have tested nuclear weapons. In the UK, nuclear-armed Trident submarines replace the previous Polaris system.

Key dates
March 1991 The last cruise missiles leave Britain.

July 1991 The United States and the Soviet Union sign the START I treaty (Strategic Arms Reduction Treaty) on the reduction and limitation of strategic offensive arms.

March 1992 The first Trident submarine, HMS Vanguard, is launched.

March 1992 South Africa announces it has dismantled its nuclear weapons.

January 1993 START II signed.

September 1993 The Labour Party conference votes to cancel Trident and to stop nuclear testing.

January 1994 Ukraine signs an agreement with the United States and Russia to give up all the nuclear weapons deployed in the country by the former Soviet Union.

December 1994 START I enters into force.

1995 France resumes nuclear testing in the South Pacific.

December 1995 The Treaty of Bangkok, making Southeast Asia a nuclear-weapon-free-zone, is signed.

April 1996 The Treaty of Pelindaba, making Africa nuclear-weapon-free, is signed.

July 1996 The International Court of Justice issues an advisory opinion that “the threat or use of nuclear weapons would generally be contrary to the rules of international law”. It also confirmed that the nuclear weapons states had a duty to work towards nuclear disarmament under Article 6 of the Non-Proliferation Treaty.

September 1996 The United Nations General Assembly adopts the Comprehensive Test Ban Treaty, an agreement to ban all nuclear weapon testing.

May 1998 Both India and Pakistan carry out underground nuclear tests.

October 1999 The United States Senate rejects the Comprehensive Test Ban Treaty, drawing widespread international condemnation.

2000s and beyond
The beginning of the new millennium is dominated by the ‘war on terror’, in response to the September 11th attacks on the United States. More recently, a new nuclear arms race has begun, with each nuclear-armed state modernising or expanding their nuclear arsenal.

Key dates
April 2000 The Duma, Russia’s parliament, ratifies the Comprehensive Test Ban Treaty.

May 2000 After last-minute negotiations at the NPT Review Conference, the world’s five main nuclear powers pledge to make “an unequivocal undertaking… to accomplish the total elimination of their nuclear arsenals”.

June 2000 United States President Bill Clinton and Russian President Vladimir Putin reach an Early Warning Agreement during the Moscow Summit.

March 2002 UK Defence Minister Geoff Hoon tells Parliament that Britain could use nuclear weapons against non-nuclear weapon states.

June 2002 US withdraws from the Anti-Ballistic Missile Treaty.

January 2003 North Korea withdraws from the nuclear Non-Proliferation Treaty.

January 2003 The CIA reports that Iran is pursuing a nuclear weapons programme.

February 2003 Demonstrations take place across the world against an invasion of Iraq. The largest ever demonstration in British history – organised by CND, Stop the War Coalition and Muslim Association of Britain – is held in London, with over a million people present.

March 2003 UK is part of coalition which invades Iraq.

March 2007 UK Parliament votes to begin process of replacing Trident with a new submarine-based delivery system for its nuclear weapons.

July 2015 The Joint Comprehensive Plan of Action, commonly known as the Iran nuclear deal, is agreed.

February 2016 CND organises Scrap Trident demonstration in London, with 100,000 protesting against Britain’s nuclear weapons system.

July 2016 UK Parliament votes to build new submarines for the UK’s nuclear weapons system.

July 2017 The first treaty to ban nuclear weapons outright – the Treaty on the Prohibition of Nuclear Weapons – is adopted at the United Nations.

December 2017 The International Campaign to Abolish Nuclear Weapons (ICAN) – of which CND is a partner – wins the Nobel Peace Prize for its work on the Treaty on the Prohibition of Nuclear Weapons.

February 2020 The UK government is forced to announce it has begun work on a new nuclear warhead, following comments by US officials revealing the work had begun.

January 2021 The Treaty on the Prohibition of Nuclear Weapons enters into force.

March 2021 UK government announces it will increase its number of nuclear warheads by over 40%.

CND campaigning against Trident