pre-1940 | 1940s | 1950s | 1960s | 1970s | 1980s | 1990s | 2000s
1896
Discovery of radioactivity.
1929
July 24: Kellogg-Briand Pact, which bans war as an instrument of foreign policy, is proclaimed.
1939
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August 2: Albert Einstein sends a letter to President Franklin D. Roosevelt informing him of German atomic research and the potential for a bomb. This letter prompts Roosevelt to form a special committee to investigate the military implications of atomic research. (DOE) |
1940
Brazilian President Getulio Vargas initiates a national nuclear program. He allows the United States to mine Brazil’s large uranium reserves in return for American nuclear technology. (FAS)
1942
July 13: The Manhattan Project, the top secret project to build an atomic bomb, gets officially underway.
December 2: A Manhattan Project team headed by Enrico Fermi produces the first artificial fission reaction at the University of Chicago. Soon after, a complex of top-secret nuclear production and research facilities are built by the Manhattan Project across the country. By 1945, the operation would have a payroll, facilities, and labor force comparable in size to the American automobile industry. (DOE)
1943
November: The Clinton Pile (located in Oak Ridge, Tennessee, and renamed Oak Ridge National Laboratory after the war) begins operation. It is the first true plutonium production reactor. (DOE)
1944
March 13: Homi Jehangir Bhabha initiates efforts to start nuclear research programs in India.
December 8: Joseph Rotblat, Polish refugee and physicist, resigns from the Manhattan Project because he believes that Nazi Germany would not succeed in developing an atomic weapon. Rotblat was thereafter barred from entering the United States for twenty years. (NF)
1945
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April 12: When President Franklin D. Roosevelt dies, Harry S. Truman becomes the U.S. president. He was never briefed by Roosevelt on the development of the atomic bomb or other key issues. |
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July: Clement Attlee becomes the British Prime Minister, replacing Winston Churchill. |
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July 16, 5:29 am: The United States conducts the world’s first nuclear test explosion at Alamogordo, New Mexico. |
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August 9: At 11:02 a.m., another B-29 drops the second bomb, a plutonium device dubbed "Fat Man," on the industrial section of the city of Nagasaki.
The bomb totally destroys 1 1/2 square miles of the city, killing 39,000 persons, and injuring 25,000 more. (Trinity: Manhattan Report) |
August 10: The Japanese government requests that it be permitted to surrender under the terms of the Potsdam declaration of July 26th which it previously ignored. (Trinity: Manhattan Report)
August 14: Japan surrenders, though on terms different from the Potsdam declaration. The emperor is allowed to remain at the head of the government, although American military forces occupy the nation and the Japanese constitution prevents the development of a military.
December 19: Nuclear research begins in India with the establishment of Tata Institute of Fundamental Research with Homi Jehangir Bhabha as its first director. (NF)
1946
January 24: The UN General Assembly adopts its first resolution, which calls for ‘the elimination from national armaments of atomic weapons and all other major weapons adaptable to mass destruction.’ (NF)
March: The Acheson-Lilienthal Plan results from US Secretary of State James Byrnes’ committee to study the "control and safeguards" of atomic information. The plan calls for the international sharing of this information. However, it is presented to the United Nations by Bernard Baruch in a revised form that is unacceptable to the Soviet Union. In June, the Soviets present the Gromyko plan, but negotiations break down.
July: The Atomic Energy Act is passed, establishing the Atomic Energy Commission. The AEC replaces the Manhattan Project on December 31, 1946. Further development of nuclear technology is under civilian (not military) control. (DOE)
1947
January: Vincent Auriol becomes French president.
August: The United Kingdom’s first atomic reactor at Harwell comes into operation. (NF)
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August: After India gains independence, Jawaharlal Nehru becomes India’s first prime minister. |
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August: Liaquat Ali Khan becomes Pakistan’s first prime minister when it is granted statehood. |
1948
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June: The Soviet Union begins the Berlin Blockade, cutting West Berlin off from West Germany. The United States conducts a vast airlift to keep West Berlin supplied with food and fuel. The airlift continues until May 1949, when the Soviets lift the blockade. American officials discuss the possibility of the use of tactical nuclear weapons if the conflict escalates. The incident encourages American policymakers to place nuclear weapons in Europe as a tripwire to deter the conventionally superior Soviet Union from invading. |
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David Ben-Gurion become Israel’s first prime minister when Israel gains nationhood status. |
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Kim Il Sung becomes North Korea’s first premier and ruler. |
1949
January: United States President Harry Truman is sworn in for his first full term.
August 29: The Soviet Union detonates its first atomic bomb in Kazakhstan.
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October 1: Mao Zedong becomes the chairman of the newly founded People’s Republic of China. |
The Weizmann Institute of Science in Israel actively supports nuclear research.
1950
January: President Harry Truman orders the Atomic Energy Commission to develop the hydrogen bomb. The development of the bomb will be led by physcist Edward Teller, who believes that it is vital for the United State to develop the hydrogen bomb before the Soviet Union does. (PBS, DOE)
April 11: A B-29 Bomber carrying a nuclear bomb crashes into a mountain near Kirtland Air Force Base in New Mexico. The bomb is destroyed but the accompanying nuclear capsule, which has not been inserted into the bomb, remains intact. (NF)
June 25: The Korean War begins when North Korea invades South Korea.
December 9: General Douglas MacArthur requests discretionary authority to use atomic weapons during the Korean War. (NF)
1951
Sen. Brien McMahon calls for an "all-out" nuclear weapons program. (Schwartz 19)
Winston Churchill regains the post of British prime minister.
Guy Mollet succeeds Leon Blum as French premier.
April 6: President Harry Truman approves military request to use atomic weapons in Manchuria if large numbers of Chinese troops join the Korean War or if bombers are launched against United Nations forces from Manchurian bases. (NF)
April 11: President Truman discharges General MacArthur for insubordination after MacArthur repeatedly criticizes the limited objectives of the war in Korea. (NF)
October 16: Khan is assassinated. Khwaja Nazimuddin succeeds him as Pakistani prime minister.
1952
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November 1: The United States detonates the first hydrogen bomb, 10.4 megaton Mike, at Enewetak Atoll in the Marshall Islands. The explosion is nearly 700 times more powerful than the bomb exploded at Nagasaki. (NF) |
1953
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January: Dwight D. Eisenhower is sworn in as U.S. president. |
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March 5: Joseph Stalin dies. Initially Nikita S. Khrushchev, Georgi M. Malenkov and Lavrenti P. Beria collectively share power. Beria is accused of conspiracy and shot in December. |
July 27: An armistice is signed ending the war in Korea. (NF)
August: General Edmundson leads ‘Operation Big Stick’, which is a mission to destroy the Communist supply complex based on Sibyon-ni section of Korea and regain Kaesong. The mission requires him to take twenty B-36s, armed with nuclear weapons, to Okinawa in Japan. (NF)
August 8: Soviet Premier Georgi Malenkov announces that the USSR possesses the hydrogen bomb. It is tested nine months later. The development of the hydrogen bomb in the United States and the Soviet Union is regarded as the start of the Cold War arms race. (PBS)
December 8: President Dwight Eisenhower, in a United Nations address, proposes Atoms for Peace, a program to extend American aid to other countries for establishing nuclear reactors for peaceful research. Eisenhower calls for the nuclear weapons states to give part of their nuclear stockpiles to a United Nations-supervised bank of fissionable materials in an attempt to strip nuclear energy of its military casing and adapt it to the arts of peace. (NF)
Muhammad Ali succeeds Khwaja Nazimuddin as Pakistani prime minister.
1954
January: U.S. Secretary of State John Foster Dulles announces U.S. policy of massive retaliation. The policy shifts the focus from large, local military commitments to deterrence through the threat of massive retaliation -- possibly, and even probrably, including nuclear force.
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January 21: The USS Nautilus (SSN 571), the world’s first nuclear-powered submarine, is launched by the United States Navy. (NF) |
April 10: President Dwight Eisenhower sends Secretary of State John Foster Dulles to offer two atomic bombs to the French for use in their war against the Vietnamese. The offer is refused. (NF)
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September 12: U.S. Joint Chiefs of Staff recommend using atomic bombs on China in conflict over Chiang Kai-shek’s troops on Quemoy and Matsu islands. (NF) |
1955
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February: Malenkov is forced to resigned and Khrushchev becomes the undisputed leader of the USSR. |
March 15: U.S. Secretary of State John Foster Dulles tells press that the U.S. is seriously considering using atomic weapons over Quemoy-Matsu dispute with China. (NF)
March 16: President Eisenhower states publicly, ‘A-bombs can be used… as you would use a bullet.’ This causes an international uproar. NATO foreign ministers oppose a nuclear attack on China. (NF)
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July 9: The Russell-Einstein Manifesto calls on legislators, scientists, and the general public to resolve that "In view of the fact that in any future world war nuclear weapons will certainly be employed, and that such weapons threaten the continued existence of mankind, we urge the governments of the world to realize, and to acknowledge publicly, that their purpose cannot be furthered by a world war, and we urge them, consequently, to find peaceful means for the settlement of all matters of dispute between them." |
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Winston Churchill resigns. Anthony Eden becomes British Prime Minister. |
Muhammad Ali’s term as Pakistani prime minister ends. A period of frequent cabinet crises and widespread corruption ensues.
1956
July 27: A U.S. bomber crashes into a storage igloo containing three Mark 6 nuclear bombs at Lakenheath Royal Air Force base in the United Kingdom. The resulting fire damages the bombs, but fails to ignite their conventional explosive triggers. (NF)
November: The Soviet Union threatens to use rockets against London, Paris and Israel if the three nations do not end their invasion of Egypt during the Suez Canal crisis. Although the threats are generally regarded as a bluff (and did not specify a nuclear attack against the targets), the overall danger of a Cold War escalation influenced the United States to pressure France and Britain to accept a cease-fire.
1957
January: Eisenhower is sworn in for his second term as U.S. president.
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January: Anthony Eden resigns. Harold MacMillan succeeds him as British Prime Minister. |
March 10: A U.S. Air Force B-47 bomber flying from Florida to Europe with two capsules of nuclear materials for bombs fails to meet its aerial refueling plane. No traces are ever found. (NF)
May 15: The United Kingdom tests its first thermonuclear weapon at the Christmas Islands in the Pacific. (NF)
July 29: The United Nations establishes the International Atomic Energy Agency (IAEA) to promote peaceful uses of nuclear energy. (NF)
September: The United States sets off its first underground nuclear test in a mountain tunnel in the remote desert 100 miles from Las Vegas. (DOE)
September 29: A breakdown in the cooling system of a tank holding 70,000-80,000 tons of radioactive sludge causes an explosion at the Mayak complex in the Soviet Union. A plume of radioactive fallout is released. (NF)
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October: The Soviet Union stuns Americans by launching a missile carrying the earth’s first artificial satellite. If Soviet scientists could launch a Sputnik, U.S. analysts reason, they would soon be able to loft nuclear warheads to the United States. The implications are profound: warning times decrease from hours to minutes and, more importantly, there is no known means of defending against a ballistic missile attack. (Schwartz 16) |
November 8: The United Kingdom successfully tests its first hydrogen-fusion weapon.
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Pugwash Conferences on Science and World Affairs. |
1958
January 15: Linus Pauling and his wife Eva Helen Pauling present to United Nations Secretary-General Dag Hammarskjold a ‘Petition to the United Nations Urging the International Agreement to Stop the Testing of Nuclear Bombs Be Made Now,’ signed by 11,021 scientists. (NF)
March 11: A B-47 bomber accidentally drops a nuclear weapon over Mars Bluff, South Carolina. The conventional explosive trigger detonates, leaving a crater 75 feet wide and 35 feet deep. (NF)
March 25: The German Bundestag approves deployment of U.S. nuclear weapons in West Germany. (NF)
September 6: In the second Quemoy-Matsu crisis with China, General Twining of the U.S. Joint Chiefs of Staff asks President Eisenhower to give the 7th Fleet Commander authority to order nuclear strikes against China. Eisenhower refuses. (NF)
September 7: The Soviet Union informs Eisenhower that they will come to China’s aid in the event of a U.S. nuclear attack on China. (NF)
October: Gen. Muhammad Ayub Khan takes control of the Pakistani government, asusming presidential powers and ruling by decree.
October 31: President Eisenhower declares a moratorium on all nuclear testing with the understanding that the Soviet Union will also honor the moratorium.
China breaks with the Soviet Union.
1959
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January: Fidel Castro topples the Batista regime and takes control of Cuba. |
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January: Charles de Gaulle declares the Fifth Republic and succeeds Rene Coty as French president. |
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October 31: The United States deploys the first operational intercontinental ballistic missile (ICBM), the Atlas D. |
December 1: The Antarctic Treaty, which prohibits nuclear explosions and disposal of radioactive waste in Antarctica, is signed.
1960
February 13: France explodes its first atomic bomb in the Sahara desert. It has a yield of 60-70 kilotons. (NF)
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June: Soviet Premier Nikita Khrushchev pledges support for "wars of national liberation" in an address to the United Nations. (DOE) |
October 5: A radar malfunction causes the central war room of NORAD to receive a false top priority warning from the Thule, Greenland Ballistic Missile Early Warning System station, indicating a massive missile attack has been launched against North America.
December: The Joint Strategic Target Planning Staff complete SIOP 62. This war plan calls for the launch of more than 3,000 nuclear weapons – including hundreds of hydrogen bombs – to attack 1,000 separate targets in the Communist bloc in the first few hours of conflict. (NF)
1961
January 3: Control rods are removed in error from the core of a military experimental reactor near Idaho Falls, Idaho, causing a steam explosion that kills three technicians. One of them is impaled by a control rod. (NF)
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January: John F. Kennedy is sworn in as U.S. president. |
January 23: A B-52 bomber carrying two 24 megaton bombs crashes at Goldsboro, North Carolina. On one of the bombs, five of six interlocking safety devices fail, and a single switch prevents detonation. (NF)
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April: The Bay of Pigs Invasion fails. A group of Cuban exiles, trained by the CIA and supported by the American government, attempted to invade Cuba and overthrow Castro; they were quickly killed or captured. The debacle may have helped pave the way for the Cuban Missile Crisis of October 1962. |
June 23: Antarctic Treaty enters into force.
September: Both the United States and the Soviet Union resume testing, breaking their 1958 moratorium.
September 20: The United States and the Soviet Union sign a ‘Joint Statement of Agreed Principles for Disarmament Negotiations’, the McCloy-Zorin Accords. It outlines a program for general and complete disarmament. (NF)
1962
June 4: A nuclear power source atop a Thor rocket booster falls into the Pacific Ocean when the booster has to be destroyed. (NF)
June 20: A second Thor rocket booster fails, and the nuclear power source falls into the Pacific. (NF)
September: As part of a campaign to reduce the United States’ vulnerability to nuclear attack, President Kennedy advises Americans to build fallout shelters. President Kennedy’s letter in the September issue of Life magazine sets off a wave of "shelter-mania" which lasts for about a year. (DOE)
October 16-29: The Cuban Missile Crisis. A tense standoff begins when U.S. reconnaissance discovers Soviet missiles in Cuba. The United States blockades Cuba for thirteen days while Kennedy and Khrushchev work out a behind-the-scenes deal whereby the Soviet Union publicly removes its missiles from Cuba and the United States privately removes missiles from Turkey. The crisis brings the two nations to the brink of nuclear war.
1963
April 10: An American nuclear submarine, Thresher, sinks in the North Atlantic, killing all 129 crewmen. (NF)
April 11: The Vatican releases the Encyclical Letter Pacem in Terris by Pope John XXIII which calls for an end to the nuclear arms race. (NF)
June 10: President Kennedy declares a unilateral moratorium on atmospheric nuclear testing. (NF)
June 20: The United States and the Soviet Union establish a radio and telegraph Hot Line between the two governments to prevent possible accidents.
August 5: The Partial Test Ban Treaty , or the Treaty Banning Nuclear Weapon Tests in the Atmosphere, in Outer Space and Under Water, is signed in Moscow. It enters into force on October 10. (NF)
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November 22: Kennedy is assassinated in Dallas, Texas. Lyndon B. Johnson assumes the U.S. presidency. |
Harold MacMillan resigns as British prime minister.
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Ben-Gurion resigns. Levi Eshkol succeeds him as Israeli prime minister. |
1964
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October: Khrushchev is removed from power due to domestic opposition. Leonid I. Brezhnev, though sharing power with Alexei Kosygin, emerges as his successor as Soviet leader. |
October 16: China explodes its first atomic bomb at Lop Nor testing site in Sinkiang Province. (NF)
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Harold Wilson becomes British prime minister. |
Shri Lal Bahudur Shastri succeeds Nehru as Indian prime minister after the latter’s death.
1965
January: Johnson is sworn in for his first full term as U.S. president.
Between 1957 and 1965, 100 kilograms of uranium 235 disappears from a nuclear scrap recycling plant in Apollo, Pennsylvania. The material was weapons grade and suitable for making more than one bomb. The president of the firm was reported to have close ties with Israel. The mystery was never solved. (NF)
December 5: A nuclear-armed airplane rolls off the aircraft carrier USS Ticonderoga and sinks in 16,000 feet of water off the coast of Japan. (NF)
1966
January 17: A B-52 bomber carrying nuclear weapons has a midair accident while refueling and drops four nuclear weapons on Palomares, Spain. Although no nuclear explosion occurs, conventional explosions in two of the weapons scatter radioactive material over a populated area. (NF)
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Indira Gandhi succeeds Shastri as Indian prime minister after the latter’s death. |
B.J. Vorster becomes prime minister of South Africa.
1967
January 27: The Outer Space Treaty, or the Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, Including the Moon and Other Celestial Bodies, is signed in Washington, Moscow and London. It enters into force on October 10.
February 14: The Treaty for the Prohibition of Nuclear Weapons in Latin America, or Treaty of Tlatelolco, is signed at Mexico City.
June 17: China conducts its first thermonuclear weapon test. (NF)
October 5: Failure of a sodium cooling system causes a partial core meltdown at the Enrico Fermi demonstration breeder reactor 30 miles from Detroit. (NF)
1968
January 21: A B-52 bomber crashes on the sea ice off Thule, Greenland, after the crew bail out over the Thule Air Force Base. The high explosive components of all four nuclear weapons aboard detonate scattering plutonium over the ice. The United States must remove hundreds of tons of radioactive ice. (NF)
March 8-10: A Soviet Golf-II class submarine with three nuclear-armed missiles aboard sinks 750 miles off the coast of Oahu in the Hawaiian island chain. (NF)
April 22: The Treaty of Tlatelolco enters into force.
May 21: The American nuclear submarine Scorpion sinks in the Atlantic near the Azores, killing 99 crewmen. (NF)
May 24: An accident aboard the Soviet nuclear submarine K-27 kills five crew members. After unsuccessfully attempting to repair the submarine, the Soviets scuttle it along with its nuclear fuel near Novaya Zemlya. (NF)
July 1: The Treat on the Non-Proliferation of Nuclear Weapons is signed at Washington, Moscow and London.
The coaster Scheersberg-A sets sail from Antwerp to Genoa with two hundred tons of uranium. The boat does not arrive in Italy as scheduled but in Iskenderun, Turkey, empty of its cargo. Years later the owner of the ship was located in a Norwegian prison and identified as an Israeli secret agent. (NF)
August 24: France tests its first hydrogen bomb at Fangataufa Atoll in the South Pacific. (NF)
Production of nuclear weapons begins in Israel.
1969
January 14: A bomb is accidentally dropped on the deck of the nuclear-powered aircraft carrier USS Enterprise, killing 25 and wounding 85 crewmen. (NF)
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January: Richard M. Nixon is sworn in as U.S. president. |
April: Georges Pompidou succeds Charles de Gaulle as French president.
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Eshkol dies. Golda Meir succeeds him as Israeli prime minister. |
Gen. Ayub Khan resigns and Gen. Agha Muhammad Yahya Khan succeeds him as Pakstani leader.
Hot cells, used to reprocess reactor fuel to make plutonium for nuclear weapons, begin operation in Argentina. They will remain in operation, without safeguards, through 1972.
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