6 August 1945
The Enola Gay, a U.S. Army Air Corps B-29 bomber, drops the atomic bomb "Little Boy" on Hiroshima.
--Richard Rhodes, "Tongues of Fire," Chapter 19 in The Making of the Atomic Bomb (New York: Simon & Schuster, 1986).

9 August 1945
Bock's Car, a U.S. Army Air Corps B-29 bomber, drops the atomic bomb "Fat Man" on Nagasaki.
--Richard Rhodes, "Tongues of Fire," Chapter 19 in The Making of the Atomic Bomb (New York: Simon & Schuster, 1986).

August 1945
In a discussion with American reporter Louis Strong, Mao Zedong says, "the atomic bomb is a paper tiger that the U.S. reactionaries use to scare people. It looks terrible, but in fact it isn't. Of course, the atom bomb is a weapon of mass destruction, but the outcome of war is decided by the people, not by one or two new types of weapons."
--Mingquan Zhu, "The Evolution of China's Nuclear Nonproliferation Policy," Nonproliferation Review, Winter 1997, p. 41.

1 October 1949
The Chinese Communist Party establishes the People's Republic of China in Beijing.
--John Wilson Lewis and Xue Litai, China Builds the Bomb (Stanford, California: Stanford University Press, 1988), p. 5.

1 November 1949
China establishes the Chinese Academy of Sciences by merging the Academia Sinica in Nanjing and the Beiping Academy in Beijing.
--John Wilson Lewis and Xue Litai, China Builds the Bomb (Stanford, California: Stanford University Press, 1988), p. 43.

14 February 1950
China and the Soviet Union sign the "Sino-Soviet Treaty of Friendship, Alliance and mutual Assistance."
--Ministry of Foreign Affairs, the People's Republic of China, "Conclusion of the 'Sino-Soviet Treaty of Friendship, Alliance and Mutual Assistance'," 17 November 2000, <http://www.fmprc.gov.cn/eng/ziliao/3602/3604/t18011.htm>; John Wilson Lewis and Xue Litai, China Builds the Bomb (Stanford, California: Stanford University Press, 1988), p. 7.

17 July 1950
General Douglas MacArthur tells U.S. Army Department officials in Tokyo about his plan for an amphibious invasion behind enemy lines and to "destroy North Korea." MacArthur also says he sees "a unique use of the atomic bomb--to strike a blocking blow" in case China entered the war.
--Bruce Cumings, "Introduction: The Course of Korean-American Relations, 1943-1953," in Bruce Cumings, ed., Child of Conflict: The Korean-American Relationship 1943-1953 (Seattle: University of Washington Press, 1983), p. 53.

October 1950
China enters the Korean War.
--John Wilson Lewis and Xue Litai, China Builds the Bomb (Stanford, California: Stanford University Press, 1988), pp. 7-8; Stanley Weintraub, "To the Yalu," Chapter 11 in MacArthur's War: Korea and the Undoing of an American Hero (New York: Simon & Schuster, 2000), pp. 196-220.

30 November 1950
During a press conference, President Truman is asked if the United States would consider using the atomic bomb in Korea, and he replies, "There has always been active consideration of its use. I don't want to see it used. It is a terrible weapon, and it should not be used on innocent men, women and children who have nothing to do with this military aggression--that happens when it's used." The statement is very controversial, and draws strong international criticism, even from U.S. allies.
--Stanley Weintraub, MacArthur's War: Korea and the Undoing of an American Hero (New York: Simon & Schuster, 2000), pp. 257-259; Roger Dingman, "Atomic Diplomacy During the Korean War," International Security, Vol. 13, No. 3, Winter 1988/1989, pp. 65-66; Peter Hayes, Pacific Powderkeg: American Nuclear Dilemmas in Korea (Lexington: Lexington Books, 1991), p. 11.

9 December 1950
General Douglas MacArthur "requests commander's discretion to use atomic weapons."
--Bruce Cumings, The Origins of the Korean War: Volume II, The Roaring of the Cataract 1947-1950 (Princeton: Princeton University Press, 1990), p. 750.

24 December 1950
General Douglas MacArthur sends a list of targets to the Pentagon and asks for 34 atomic bombs to create "a belt of radioactive cobalt across the neck of Manchuria so that there could be no land invasion of Korea from the north for at least 60 years."
--Stanley Weintraub, MacArthur's War: Korea and the Undoing of an American Hero (New York: Simon & Schuster, 2000), pp. 263-264; Bruce Cumings, The Origins of the Korean War: Volume II, The Roaring of the Cataract 1947-1950 (Princeton: Princeton University Press, 1990), p. 750; Peter Hayes, Pacific Powderkeg: American Nuclear Dilemmas in Korea (Lexington: Lexington Books, 1991), pp. 9-10.

1951
China sends scientist Wang Ganchang to North Korea to "collect radioactive material."
--Joseph S. Bermudez, Jr., "N Korea--Set To Join the 'Nuclear Club'?" Jane's Defence Weekly, Vol. 12, No. 12, 23 September 1989, p. 594.

1952
China sends scientist Wang Ganchang to North Korea to "collect radioactive material."
--Joseph S. Bermudez, Jr., "N Korea--Set To Join the 'Nuclear Club'?" Jane's Defence Weekly, Vol. 12, No. 12, 23 September 1989, p. 594; John Wilson Lewis and Xue Litai, China Builds the Bomb (Stanford, California: Stanford University Press, 1988), p. 146.

27 January 1952
In a private hand-written memorandum, President Truman considers the possibility of using nuclear war to end the stalemate in the cease-fire talks in Panmunjom. "This means all-out war. It means that Moscow, St. Petersburg, Mukden, Vladivostok, Peking, Shanghai, Port Arthur, Darien, Odessa, Stalingrad and every manufacturing plant in China and the Soviet Union will be eliminated." The memo becomes publicly available in 1972.
--"Truman, in 1952 Memos, Considered Nuclear Strike," New York Times, 3 August 1980, p.22, in Lexis-Nexis, <http://web.lexis-nexis.com>.

18 May 1952
In a private hand-written memorandum, President Truman addresses his concerns over the failure of the Korean truce talks. "Now do you want an end to hostilities in Korea or do you want China and Siberia destroyed? You may have one or the other; whichever you want, these lies of yours at this conference have gone far enough. You either accept our fair and just proposal or you will be completely destroyed." This memo becomes publicly available in 1972.
--"Truman, in 1952 Memos, Considered Nuclear Strike," New York Times, 3 August 1980, p. 22, in Lexis-Nexis, <http://web.lexis-nexis.com>.

Mid-1952
The Joint Chiefs of Staff ask President Truman to authorize the deployment of "non-nuclear components to forward areas" in Pacific theater bases under U.S. control (Alaska, Guam, Hawaii, and Okinawa) in case the security situation worsened in East Asia.
--Robert S. Norris, William N. Arkin and William Burr, "Where They Were," The Bulletin of the Atomic Scientists, Vol. 55, No. 6, November/December 1999, p. 30.

31 March 1953
During a Special National Security Council Meeting, President Eisenhower outlines two goals if atomic weapons are to be used during the Korean War. Despite the lack of good tactical targets, using atomic weapons will be worth the cost if the U.S. can "achieve a substantial victory over the communist forces, and get to a line at the waist of Korea." President Eisenhower and Secretary of State Dulles agree that the taboo surrounding nuclear weapons would have to be destroyed.
--"For Eisenhower, 2 Goals if Bomb was to be Used," New York Times, 8 June 1984, p. A8, in Lexis-Nexis, <http://web.lexis-nexis.com>.

8 April 1953
According to a U.S. Special Intelligence Advisory Committee Estimate, the communist forces in Korea would recognize the use of atomic weapons as "indicative of Western determination to carry the Korean War to a successful conclusion." However, the report is unable to conclude whether or not this would be sufficient to coerce the communist forces to make the concessions necessary for reaching an armistice arrangement. The report says, "We believe the communist reaction would be in large part determined by the extent of damage inflicted."
--"For Eisenhower, 2 Goals if Bomb Was to Be Used," New York Times, 8 June 1984, p. A8, in Lexis-Nexis, <http://web.lexis-nexis.com>.

13 May 1953
During a National Security Council Meeting, Generals Bradley and Hull recommend that the use of atomic weapons would be necessary if military operations are expanded outside of Korea. President Eisenhower expresses his belief that using tactical atomic weapons against Chinese communists forces in dugout bunkers would be more cost effective than current conventional weapons.
--"For Eisenhower, 2 Goals if Bomb Was to Be Used," New York Times, 8 June 1984, p. A8, in Lexis-Nexis, <http://web.lexis-nexis.com>.

20 May 1953
During a National Security Council Meeting, President Eisenhower concludes that if the U.S. wishes to pursue a more positive action on North Korea, the war would need to be expanded beyond Korea and it would be necessary to use atomic weapons. Eisenhower expresses concern about the Soviet response, but dismisses any Chinese retaliation as "the blow would fall so swiftly and with such force as to eliminate Chinese communist intervention."
--"For Eisenhower, 2 Goals if Bomb Was to Be Used," New York Times, 8 June 1984, p. A8, in Lexis-Nexis, <http://web.lexis-nexis.com>.

21 May 1953
U.S. Secretary of State Dulles meets with Indian Prime Minister Jawaharlal Nehru. During talks, Dulles says that if the Korean armistice negotiations fail, "the United States would probably make a stronger, rather than a lesser military exertion, and that this might well extend the area of conflict." This veiled threat is expected to be relayed to the Chinese.
--Bernard Gwertzman, "U.S. Papers Tell of '53 Policy to Use A-Bomb in Korea," New York Times, 8 June 1984, p. A8, in Lexis-Nexis, <http://web.lexis-nexis.com>.

27 July 1953
The Korean War Armistice is signed. Some people believe that President Eisenhower's implicit threats to use nuclear weapons result in the armistice.
--"Agreement between the Commander-in-Chief, United Nations Command, on the One Hand, and the Supreme Commander of the Korean People's Army and the Commander of the Chinese People's Volunteers, on the Other Hand, Concerning a Military Armistice in Korea," signed at Panmunjŏm, 27 July 1953; Rosemary J. Foot, "Nuclear Coercion and the Ending of the Korean Conflict," International Security, Vol. 13, No. 3, Winter 1988/1989, pp. 92-93; Rosemary J. Foot, The Wrong War: American Policy and the Dimensions of the Korean Conflict, 1950-1953 (Ithaca: Cornell University Press: 1985), pp. 204-231; Peter Hayes, Pacific Powderkeg: American Nuclear Dilemmas in Korea (Lexington: Lexington Books, 1991), pp. 12-16.

3 December 1953
During a National Security Council Meeting, President Eisenhower expresses his view that "if the Chinese communist forces attack us again, the United States should respond by hitting them hard" and initiating all-out war against China. This would involve air strikes from Shanghai all the way north.
--"For Eisenhower, 2 Goals if Bomb Was to Be Used," New York Times, 8 June 1984, p. A8, in Lexis-Nexis, <http://web.lexis-nexis.com>.

1954
A prospecting team discovers uranium deposits in Guangxi Province.
--John Wilson Lewis and Xue Litai, China Builds the Bomb (Stanford, California: Stanford University Press, 1988), p. 75.

7 January 1954
The U.S. State Department and the Joint Chiefs of Staff send a memorandum to the National Security Council that recommends the use of nuclear weapons if communist forces renew military operations in Korea. The memorandum calls for the use of nuclear weapons in air operations against military targets in Korea, and against military targets in Manchuria and China that are in direct support of military operations in Korea.
--"For Eisenhower, 2 Goals if Bomb Was to Be Used," New York Times, 8 June 1984, p. A8, in Lexis-Nexis, <http://web.lexis-nexis.com>.

January 1955
The senior leadership of the Chinese Communist Party decides to pursue a nuclear weapons program.
--John Wilson Lewis and Xue Litai, "The Strategic Decision and Its Consequences," Chapter Three in China Builds the Bomb (Stanford, California: Stanford University Press, 1988), pp. 35-72.

17 January 1955
The Soviet government announces that it will assist China and several Eastern European countries pursue "research into the peaceful uses of atomic energy."
--John Wilson Lewis and Xue Litai, China Builds the Bomb (Stanford, California: Stanford University Press, 1988), p. 41; Alice Langley Hsieh, Communist China's Strategy in the Nuclear Era (Englewood Cliffs, New Jersey: Prentice Hall, 1962), pp. 20-21.

20 January 1955
China and the Soviet Union sign an agreement for joint surveys of uranium in China. China agrees to sell any surplus uranium to the Soviet Union.
--John Wilson Lewis and Xue Litai, China Builds the Bomb (Stanford, California: Stanford University Press, 1988), pp. 41, 76.

March 1955
China's State Council establishes the Third Bureau under the Ministry of Geology. The bureau is tasked with a national uranium prospecting program.
--John Wilson Lewis and Xue Litai, China Builds the Bomb (Stanford, California: Stanford University Press, 1988), p. 76.

27 April 1955
China and the Soviet Union sign an agreement for Soviet assistance for research on nuclear physics and the peaceful use of atomic energy. The agreement also includes a provision for the Soviet Union to supply a nuclear reactor and a cyclotron.
--John Wilson Lewis and Xue Litai, China Builds the Bomb (Stanford, California: Stanford University Press, 1988), pp. 41, 105.

1 July 1955
The State Council establishes the Bureau of Architectural Technology. The name is deceptive as the bureau will supervise the delivery and construction of a Soviet-supplied research reactor and cyclotron.
--John Wilson Lewis and Xue Litai, China Builds the Bomb (Stanford, California: Stanford University Press, 1988), p. 47.

4 July 1955
The Chinese Communist Party Politburo appoints a three-member group under its direct authority to direct policymaking for the nuclear weapons program. They are Chen Yun, Nie Rongzhen, and Bo Yibo.
--John Wilson Lewis and Xue Litai, China Builds the Bomb (Stanford, California: Stanford University Press, 1988), pp. 46-47.

October 1955
A Chinese delegation visits the Soviet Union to study the theory and operation of nuclear reactors, cyclotrons and other nuclear-related hardware. However, the group does not get access to military-related research or facilities.
--John Wilson Lewis and Xue Litai, China Builds the Bomb (Stanford, California: Stanford University Press, 1988), p. 106.

November 1955
A second Chinese delegation visits the Soviet Union to study the theory and operation of nuclear reactors, cyclotrons and other nuclear-related hardware. However, the group does not get access to military-related research or facilities.
--John Wilson Lewis and Xue Litai, China Builds the Bomb (Stanford, California: Stanford University Press, 1988), p. 106.

1956
The United States begins to deploy nuclear weapons to bases in Guam, Hawaii, and Okinawa.
--Robert S. Norris, William N. Arkin and William Burr, "Where They Were," The Bulletin of the Atomic Scientists, Vol. 55, No. 6, November/December 1999, p. 30.

17 August 1956
China and the Soviet Union sign an agreement whereby Moscow will assist Beijing in building nuclear industry and research facilities.
--John Wilson Lewis and Xue Litai, China Builds the Bomb (Stanford, California: Stanford University Press, 1988), p. 41.

16 November 1956
The State Council establishes the Third Ministry of Machine Building to direct the country's nuclear industry. The ministry replaces the Politburo's three-member group, which was responsible for China's nuclear weapons policy.
--John Wilson Lewis and Xue Litai, China Builds the Bomb (Stanford, California: Stanford University Press, 1988), pp. 48-49.

1957
Chairman Mao Zedong estimates that between one-third and one-half of the world's population would die in a nuclear war.
--Chinese Government Statement, 1 September 1963, cited in Alice Langley Hsieh, "The Sino-Soviet Nuclear Dialogue: 1963," The Journal of Conflict Resolution, Vol.8, No. 2, June 1964; Mingquan Zhu, "The Evolution of China's Nuclear Nonproliferation Policy," Nonproliferation Review, Winter 1997, p. 41.

15 October 1957
China and the Soviet Union sign the "New Defense Technical Accord." Under the terms of the agreement, the Soviet Union will provide China with a prototype nuclear bomb, missiles, and related data. [Note: Moscow later reneges and refuses to provide Beijing with a nuclear device].
--John Wilson Lewis and Xue Litai, China Builds the Bomb (Stanford, California: Stanford University Press, 1988), pp. 41, 62-64; Mingquan Zhu, "The Evolution of China's Nuclear Nonproliferation Policy," Nonproliferation Review, Winter 1997, pp. 41-42.

15 October 1957
Song Renqiong, Third Machine Building Minister, approves the construction order for China's first nuclear power plant.
--John Wilson Lewis and Xue Litai, China Builds the Bomb (Stanford, California: Stanford University Press, 1988), p. 52.

17 October 1957
Song Renqiong, Third Machine Building Minister, approves the construction order for China's second nuclear power plant.
--John Wilson Lewis and Xue Litai, China Builds the Bomb (Stanford, California: Stanford University Press, 1988), p. 52.

1958
China's Second Ministry establishes the Sixth Institute, which is also known as the Uranium Mining and Metallurgical Processing Institute. [Note: The name is later changed to the Sixth Institute].
--John Wilson Lewis and Xue Litai, China Builds the Bomb (Stanford, California: Stanford University Press, 1988), pp. 90-91.

Early 1958
According to John Lewis and Xue Litai, the Soviet Communist Party Politburo probably decides by early 1958 to renege on its commitment to provide China with an atomic bomb.
--John Wilson Lewis and Xue Litai, China Builds the Bomb (Stanford, California: Stanford University Press, 1988), pp. 60-61.

May 1958
Soviet technicians begin to advise Chinese technicians on the design of a gaseous diffusion plant.
--John Wilson Lewis and Xue Litai, China Builds the Bomb (Stanford, California: Stanford University Press, 1988), p. 118.

May 1958
China begins construction of its first uranium mine in Chenxian, Hunan Province.
--John Wilson Lewis and Xue Litai, China Builds the Bomb (Stanford, California: Stanford University Press, 1988), pp. 76-86.

June 1958
China begins operating its Soviet-supplied research reactor and cyclotron.
--John Wilson Lewis and Xue Litai, China Builds the Bomb (Stanford, California: Stanford University Press, 1988), p. 99.

August 1958
China begins construction of the Hengyang Uranium Hydrometallurgy Plant in Hunan Province.
--John Wilson Lewis and Xue Litai, China Builds the Bomb (Stanford, California: Stanford University Press, 1988), p. 95.

August 1958
According to Andrei Gromyko's memoirs, published in 1988, Soviet Foreign Minister Gromyko visits Beijing during escalating tensions over the islands of Quemoy and Matsu, which are occupied by the Republic of China on Taiwan. Mao Zedong reportedly formulates a plan to retreat to the interior of China drawing in American forces. He then calls for the Soviet Union to use "all its means" to attack the American troops. Mao argues that China can survive a nuclear war even if 300 million people are lost.
--Philip Taubman, "Gromyko Says Mao Wanted Soviet A-Bomb Used on G.I.'s," New York Times, 22 February 1988, p. A1, in Lexis-Nexis, <http://web.lexis-nexis.com>.

October 1958
The Soviet government informs Beijing that it will deliver a prototype atomic bomb and technical data in November 1958. However, the bomb is never delivered. [Note: According to John Lewis and Xue Litai, the Soviet Communist Party Politburo probably decided in early 1958 to renege on its commitment to provide China with an atomic bomb].
--John Wilson Lewis and Xue Litai, China Builds the Bomb (Stanford, California: Stanford University Press, 1988), pp. 60-61.

20 June 1959
The Soviet Communist Party Central Committee sends a letter to the Central Committee of China's Communist Party informing China that Moscow will not deliver a prototype atomic bomb to Beijing. The Soviets cite the ongoing negotiations in Geneva for a test ban treaty as the reason for reneging on the agreement to provide an atomic bomb. [Note: China names its first atomic bomb "Device 596," which represents the year and month (June 1959) in which the Soviets refused to provide the bomb. Device 596 is detonated on 16 October 1964].
--John Wilson Lewis and Xue Litai, China Builds the Bomb (Stanford, California: Stanford University Press, 1988), pp. 64-65.

September 1959
China signs a nuclear cooperation agreement with North Korea.
--Harry Gilman and Norman Levin, The Future of Soviet and North Korean Relations (Santa Monica, CA: The RAND Corporation, October 1984), p. 2; (South) Korea Atomic Energy Research Institute, "Pukhanŭi Haekkwallyŏn Yŏn'guhwaltong," <http://www.kaeri.re.kr/>.

	Updated December 2005