The Second World War ends in Europe on 7 May 1945 when Germany surrenders unconditionally. Fighting continues in the Pacific until the United States drops atomic bombs on Hiroshima and Nagasaki on 6 and 9 August 1945 respectively, killing about 120,000 people outright and fatally injuring over 100,000 more.
Japanese Emperor Hirohito surrenders unconditionally on 15 August 1945.
Following the war, Eastern European countries are occupied by the Soviet Union (USSR) and turned into "satellite states" governed by "puppet" communist regimes. An "Iron Curtain" falls across Europe and a "Cold War" develops between the USSR and the West.
The Cold War intensifies on 29 August 1949 when the USSR explodes an atomic weapon of its own. An "arms race" then begins between the US and USSR, with both sides developing huge arsenals of thermonuclear (hydrogen) bombs and Inter-Continental Ballistic Missiles (ICBMs) capable of delivering nuclear warheads across continents.
An uneasy and dangerous balance of deterrence is established under the principle of Mutually Assured Destruction (MAD).
Born on 21 May 1921 in Moscow into a cultured and liberal family belonging to the Moscow intelligentsia. His father is a physics teacher. Sakharov receives his initial education at home. He does not enter public school until the age of 13. Sakharov is a gifted student. He enrols at the faculty of physics at Moscow University immediately after completing his schooling.
1939 - German troops invade Poland on 1 September. Britain and France declare war on Germany two days later. The Second World War has begun. The Soviet Union remains neutral for the first two years of the war but is brought into the conflict after Germany invades on 22 June 1941. Sakharov is classified as medically unfit for military service. He is evacuated to Ashkhabad in Central Asia to complete his studies.
1942 - Sakharov receives his degree in physics, passing his finals with distinction. In September he is assigned to work as an engineer and inventor at a large munitions factory on the Volga River. He stays in the post throughout the war.
While working at the munitions factory be meets Klavdia Alekseyevna Vikhireva, a laboratory technician. The couple marry in 1943. They have three children.
1945 - When the war ends, Sakharov returns to Moscow and begins graduate studies at the Lebedev Institute. The institute is a specialist physics research facility within the Academy of Sciences of the USSR. Sakharov's chosen field of research is nuclear physics. He receives his doctorate in 1947.
1948 - Sakharov joins a group of research scientists working on the USSR's top-secret nuclear weapons project. He works on the nuclear weapons program for the next 20 years and becomes a key figure in the development of the Soviet hydrogen bomb.
Sakharov later says, "At the time we were all convinced that this work was of vital significance for the balance of power in the world and we were fascinated by the grandeur of the task."
"I understood, of course, the terrifying, inhuman nature of the weapons we were building. But the recent war had also been an exercise in barbarity; and although I hadn't fought in that conflict, I regarded myself as a soldier in this new scientific war."
1949 - The USSR explodes its first atomic bomb at Semipalatinsk in eastern Kazakhstan on 29 August.
1950 - Sakharov moves to the "Installation", a secret facility in the central Volga region of the USSR dedicated to the design of nuclear weapons. He works there with other team members to develop a hydrogen bomb. A hydrogen bomb uses an atomic "fission" explosion to trigger a more powerful "fusion" explosion.
1952 - Great Britain enters the nuclear race on 3 October when it explodes an atomic bomb at the Montebello Islands, off the northwest coast of Western Australia.
The United States successfully detonates a hydrogen bomb at Eniwetok Atoll (the Marshall Islands) on 1 November. Though smaller in size than the bombs exploded over Hiroshima and Nagasaki, the hydrogen bomb is 2,500 times more powerful. The island on which the bomb is tested is completed destroyed.
Over the coming decades, the number and capacity of nuclear-armed states continues to rise.
Great Britain explodes a hydrogen bomb at Christmas (Kiritimati) Island in the Pacific Ocean on 8 November 1957.
France becomes a nuclear power in 1960 when it explodes an atomic bomb at Reggane in Algeria. France successfully detonates a hydrogen bomb at Fangataufa Atoll in the South Pacific on 24 August 1968.
The Chinese explode an atomic bomb at Lop Nor in the Xinjiang Uygur Autonomous Region on 16 October 1964. They conduct their first successful test of a hydrogen bomb on 17 June 1967.
India joins the nuclear weapons club when it explodes an atomic bomb in Rajasthan on 18 May 1974.
Long-held suspicions that Israel has a well-developed nuclear weapons program are confirmed in September 1986 when Mordecai Vanunu, an Israeli arms technician, provides hard evidence of an underground bomb factory.
Pakistan conducts test explosions of nuclear devices in the Chagai Hills in Baluchistan in May 1998.
North Korea detonates a nuclear device in 2006.
1953 - The USSR conducts its first successful test of a prototype hydrogen bomb on 12 August. The bomb has been produced using a design suggested by Sakharov. His research also provides key contributions to the detonation of the USSR's first full-fledged hydrogen bomb on 22 November 1955 and to the Czar Bomb of 1961, the most powerful device ever exploded on Earth.
Meanwhile, Sakharov begins to consider the "moral problems inherent in (his) work". By 1957 he has reached the point where he feels personally responsible for "the problem of radioactive contamination from nuclear explosions". He starts to set out his views in scientific papers such as 'Radioactive Carbon from Nuclear Explosions and Nonthreshold Biological Effects' and 'The Radioactive Danger of Nuclear Tests'.
He also writes letters to the Soviet authorities, including Nikita Khrushchev, first secretary of the Communist Party, arguing that atmospheric nuclear tests should be stopped and that the USSR should accept a proposal by the US for a limited ban on tests.
1963 - Representatives from the USSR, the US and Great Britain gather in Moscow to negotiate a treaty banning nuclear tests in the atmosphere, in space, and in the ocean. Underground tests are allowed to continue. The treaty is signed on 5 August and comes into effect on 10 October.
"I consider the Moscow Treaty of historic significance," Sakharov later says. "It has saved the lives of hundreds of thousands, possibly millions, of people who would have perished had testing continued. And perhaps even more important, the treaty was a step toward reducing the risk of thermonuclear war. I am proud of my contribution to the Moscow Treaty."
1967 - Sakharov sends a secret memorandum to the Soviet leadership advising them to accept a US proposal for a moratorium on the development of anti-ballistic missile defence systems, arguing that rejection of the proposal would only lead to a further intensification of the arms race and increase the likelihood of nuclear war.
When his request that his concerns be made public is refused by the leadership, he decides to act by himself.
1968 - Sakharov distils his concerns into 'Reflections on Progress, Peaceful Coexistence and Intellectual Freedom', an essay arguing that the total annihilation of civilisation that would result from a nuclear war can only be averted by worldwide cooperation transcending national and ideological boundaries.
The essay presents two theses:
"1. The division of mankind threatens it with destruction. ... Only universal cooperation under conditions of intellectual freedom and the lofty moral ideals of socialism and labour, accompanied by the elimination of dogmatism and pressure of the concealed interests of ruling classes, will preserve civilisation. ...
"2. The second basic thesis is that intellectual freedom is essential to human society - freedom to obtain and distribute information, freedom for open-minded and unfearing debate, and freedom from pressure by officialdom and prejudices. Such a trinity of freedom of thought is the only guarantee against an infection of people by mass myths, which, in the hands of treacherous hypocrites and demagogues, can be transformed into bloody dictatorship. Freedom of thought is the only guarantee of the feasibility of a scientific democratic approach to politics, economics and culture."
Typewritten copies of the essay are circulated throughout the USSR. Copies also fall into the hands of the foreign press.
Following the publication of the essay by the Dutch newspaper 'Het Porool' and 'The New York Times' in July, Sakharov is dismissed from the nuclear weapons program and stripped of the privileges granted to those at the top of the Soviet system.
Meanwhile, the USSR, the US, Britain, France and China agree to sign the Nuclear Nonproliferation Treaty, pledging to restrict the development, deployment and testing of nuclear weapons.
The USSR and US also initiate the Strategic Arms Limitation Talks (SALT).
1969 - In March, Sakharov's wife, Klavdia, dies of cancer. Sakharov returns to the Lebedev Institute in May and begins to investigate problems connected with the theory of elementary particles, the theory of gravitation, and cosmology.
1970 - Sakharov becomes increasingly vocal about human rights. He helps found and run a committee dedicated to the pursuit of human rights reforms, including the abolition of secret trials, the introduction of a law guaranteeing freedom of the press, amnesty for political prisoners, the abolition of the death penalty, the opening of borders, and a ban on the use of psychiatric institutes for political ends.
While working in the human rights community, Sakharov meets Yelena Georgievna Bonner. The couple marry in 1972.
1972 - The SALT negotiations between the USSR and the US result in the Anti-Ballistic Missile Treaty and the Interim Agreement on the Limitation of Strategic Offensive Arms. Further SALT negotiations lead to a treaty limiting the total number of USSR and US missile launchers.
1973 - Sakharov's rising profile as a champion of human rights increases the pressure being placed on him and Yelena Bonner by the Soviet regime. In February 1973 the journal 'Literaturnaya Gazeta' prints the first official public criticism of Sakharov.
1974 - Sakharov predicts the development of the World Wide Web, almost 20 years before it first appears.
"Far in the future, more than 50 years from now, I foresee a universal information system (UIS), which will give everyone access at any given moment to the contents of any book that has ever been published or any magazine or any fact," he writes in an article published on 24 August.
"The UIS will have individual miniature-computer terminals, central control points for the flood of information, and communication channels incorporating thousands of artificial communications from satellites, cables, and laser lines. Even the partial realisation of the UIS will profoundly affect every person, his leisure activities, and his intellectual and artistic development. Unlike television ... the UIS will give each person maximum freedom of choice and will require individual activity. But the true historic role of the UIS will be to break down the barriers to the exchange of information among countries and people."
1975 - Sakharov is awarded the Nobel Peace Prize for his "fearless personal commitment in upholding the fundamental principles for peace between men". He is the first Soviet citizen to receive the prize.
The Nobel Committee calls Sakharov "a powerful inspiration for all true work for peace".
"Uncompromisingly and with unflagging strength Sakharov has fought against the abuse of power and all forms of violation of human dignity, and he has fought no less courageously for the idea of government based on the rule of law," the Committee says.
The Soviet authorities repudiate the award. Sakharov is labelled "a Judas" and "laboratory rat of the West" and prevented from travelling to Oslo to receive the award. Yelena Bonner accepts the award on his behalf and presents his acceptance speech. Sakharov's Nobel lecture, 'Peace, Progress, Human Rights', is also presented by Yelena Bonner.
"In struggling to protect human rights we must, I am convinced, first and foremost act as protectors of the innocent victims of regimes installed in various countries, without demanding the destruction or total condemnation of these regimes," the lecture says.
"We need reform, not revolution. We need a pliant, pluralist, tolerant community, which selectively and tentatively can bring about a free, undogmatic use of the experiences of all social systems. What is détente? What is rapprochement? We are concerned not with words, but with a willingness to create a better and more friendly society, a better world order."
1979 - Soviet forces invade Afghanistan in late December. Sakharov publicly denounces the invasion. Within days he is detained, stripped of all his official Soviet awards, and exiled to Gorky (now called Nizhni Novgorod), 400 km east of Moscow. He remains in exile for almost seven years, though he is never charged, tried, or convicted of any crime.
Sakharov is kept under constant surveillance while in exile. He is prohibited from leaving the city limits and from meeting with foreigners and "criminal elements". He is not allowed to communicate with his children and grandchildren. He cannot correspond with colleagues in the scientific community. He has to report three times a month to the police.
While isolated from friends and colleagues, Sakharov is still able to communicate with the outside world via Yelena Bonner, who ensures that the essays and articles he writes while in exile are published in the USSR and abroad.
Sakharov also uses his time in exile to write the first part of his 'Memoirs', though he is forced to rewrite it from memory when the Soviet secret police steal the manuscript.
1981 - Sakharov and Bonner's daughter-in-law is drawn into events when Soviet authorities refuse to grant her permission to travel to the US to join her husband. Sakharov and Bonner go on a hunger strike in protest. Sakharov is forcibly hospitalised and denied any contact with Bonner. Their daughter-in-law is, however, eventually allowed to join her husband.
1984 - Yelena Bonner is prosecuted on charges of anti-Soviet slander and sent to join Sakharov in exile in Gorky. Bonner is suffering from a heart condition but is denied adequate medical treatment. Sakharov resorts to hunger strikes to try to force the authorities to allow her to travel to the West for treatment. He is again forcibly hospitalised and denied contact with Bonner.
Meanwhile, US President Ronald Reagan launches the Strategic Defence Initiative, also known as Star Wars. Sakharov opposes the initiative, arguing that like the earlier anti-ballistic missile defence systems proposal, it would increase the likelihood of nuclear war.
1985 - Mikhail Gorbachev comes to power in the USSR and begins a program of social reform called Perestroika (reconstruction).
Bonner is finally granted permission to travel to the US for heart surgery. When she returns she is again placed in exile with her husband.
1986 - On 16 December Gorbachev invites Sakharov to return to Moscow and perform "patriotic work". Sakharov and Bonner's period of exile has come to an end.
1987 - In December Gorbachev and US President Ronald Reagan sign the Intermediate Range Nuclear Forces Treaty, which calls for the removal of many nuclear armed ballistic missiles deployed in Europe and the USSR and the destruction of all Soviet and US missiles with ranges of about 500 to 5500 km.
1988 - The European Parliament inaugurates the annual Sakharov Prize for Freedom of Thought. The prize seeks "in the spirit of Andrei Sakharov ... to honour individuals or organisations who have devoted themselves to the defence of human rights and fundamental freedoms and the struggle against oppression and injustice".
1989 - Sakharov is elected as a member of the Congress of People's Deputies (the Soviet parliament) in April. He becomes joint leader of the democratic opposition faction. In October he is elected to the Presidium (administrative committee) of the Academy of Science.
Sakharov becomes critical of Gorbachev, insisting that the Perestroika reforms should go much further. In June he appeals for a radical reformation of the Soviet system including the repeal of the clause in the constitution giving the Communist Party a monopoly on political power. In December, Sakharov completes his personal draft of a new constitution for the Union of Soviet Republics of Europe and Asia.
Sakharov's draft constitution guarantees freedom of conscience, freedom of speech, freedom of religion, freedom of association, freedom of movement and the right to privacy. It guarantees freedom from arbitrary arrest, the presumption of innocence, the separation of church and state, and freedom from discrimination based on nationality, religion, political convictions, sex, age, health and prior criminal record.
The draft constitution includes the goal of completely eliminating and prohibiting nuclear weapons and other means of mass destruction. It also prohibits the secret services from conducting operations to protect the existing order in the Union. The draft eliminates all mention of the Communist Party. It separates the government and the presidency from party political structures.
Sakharov dies of a heart attack in Moscow on 14 December.
Yelena Bonner dies on 18 June 2011.
The Communist Party relinquishes its constitutional hold over the Soviet political system in 1990. The Soviet Union breaks up into 15 separate self-governing republics. Democracy is introduced to Russia.
The Federation of American Scientists estimates that as of December 2017 there were approximately 14,550 nuclear warheads in the world. About 9,450 of these were in military stockpiles. The remainder were retired and awaiting dismantlement, although about 3,900 were deployed with operational forces.
Russia had a total inventory of 6,800 warheads. The United States had 6,600. France had 300. China had 270. The Britain had 215. Israel had 80. Pakistan had 130-140. India had 120-130. North Korea had 10-20.
Reflecting on the nuclear arms race in his 'Memoirs', Sakharov wrote:
"Have Soviet and American atomic scientists helped to keep the peace? After more than 40 years, we have had no third world war, and the balance of nuclear terror ... may have helped to prevent one. But I am not at all sure of this; back then, in those long-gone years, the question didn't even arise. What most troubles me now is the instability of the balance, the extreme peril of the current situation, the appalling waste of the arms race. ... Each of us has a responsibility to think about this in global terms, with tolerance, trust, and candour, free from ideological dogmatism, parochial interests, or national egotism."
While the threat of a global nuclear conflict may have subsided following the end of the Cold War, the danger of the "limited" use of nuclear arms by nation states or terrorist groups remains. The US, Russia, Great Britain, France, China, India, Pakistan, Israel and North Korea all possess nuclear weapons. Algeria, Argentina, Brazil, Iran, Iraq, Libya, South Africa and Taiwan have all at some stage been identified as having nuclear weapons ambitions.
The genie unleashed by Sakharov and the other pioneering nuclear scientists may never be put back into the bottle. If it is, it will require the dedication of scientists like Sakharov - people prepared to recognise that their research does not occur in a vacuum and that there are moral imperatives that should take precedence over scientific inquiry, even if this requires some personal sacrifice.
- The Andrei Sakharov Foundation
- Andrei Sakharov: Soviet Physics, Nuclear Weapons and Human Rights - American Institute of Physics
- The Nobel Peace Prize 1975 - Andrei Sakharov
- Andrei Sakharov, 68, Soviet 'Conscience,' Dies - Obituary - The New York Times