Motivation

The Chinese nuclear weapons program was initiated on 15 January 1955. The decision made by the Chinese leadership was prompted by confrontations with the United States in the 1950s, including the Korean War, the 1955 Taiwan Straits Crisis, nuclear blackmail, and eventually the Vietnam War as well.^[6] Mao Zedong explained his decision to a gathering of the Politburo of the Chinese Communist Party in 1956:

"Now we're already stronger than we were in the past, and in the future we'll be even stronger than now. Not only are we going to have more airplanes and artillery, but also the atomic bomb. In today's world, if we don't want to be bullied, we have to have this thing."^[7]

Mao was confident that nuclear weapon capabilities would allow China to assert its "national will" toward policy goals and deter threats to national security.

Design and testing

In 1956, the Third Ministry of Machinery Building was established, and nuclear research was conducted at the Institute of Physics and Atomic Energy in Beijing. A gaseous diffusion uranium enrichment plant was constructed in Lanzhou. In 1957, China and the USSR signed an agreement on sharing defense technology that involved an atomic bomb prototype being supplied by Moscow to Beijing, technical data, and an exchange of hundreds of Russian and Chinese scientists.^[8] A joint search for uranium in China was conducted between the two countries. A location near Lake Lop Nur in Xinjiang was selected to be the test site with its headquarters at Malan. Construction of the test site began on 1 April 1960, involving tens of thousands of laborers and prisoners under tough conditions.^[5] It took four years to complete. Being the sole site for nuclear testing in China for years to come, the Lop Nur test site underwent extensive expansion and is by far the world's largest nuclear weapons test site, covering around 100,000 square kilometers.^[9]

Sino-Soviet relations cooled during 1958 to 1959. China was upset by the lack of Soviet assistance in quelling the Tibetan uprisings in 1959 and against the escape of the Dalai Lama to India.^[10] The Soviet Union later refused support for China in the Sino-Indian War of 1962. Khrushchev was unnerved at Mao's relatively nonchalant view on nuclear war.^[11] The Soviet Union was also engaged in test ban negotiations with the United States in 1959 in order to relax Soviet-American tensions, directly inhibiting the delivery of a prototype to China. Broader disagreements between Soviet and Chinese communist ideologies escalated mutual criticism. The Soviets responded by withdrawing the delivery of a prototype bomb^[3] and over 1,400 Russian advisers and technicians involved in 200 scientific projects in China meant to foster cooperation between the two countries.^[10]

Project 596 was named after the month of June 1959 in which it was initiated as an independent nuclear project, immediately after Nikita Khrushchev decided to stop helping the Chinese with their nuclear program on 20 June 1959, and Mao shifted toward an overall policy of self-reliance. By 14 January 1964, enough fissionable U-235 had been successfully enriched from the Lanzhou plant. On 16 October 1964, a uranium-235 fission implosion device, weighing 1550 kilograms was detonated on a 102-meter tower.^[5]

United States

The United States government was aware of Soviet support of a Chinese nuclear program, but after the Soviets withdrew support in 1959, some U.S. officials underestimated the sole capability of China to develop a nuclear weapon, and were surprised when China's efforts proved successful. Namely, they thought there was an insufficient source for weapons-grade U-235 production and that the significance of a nuclear China was underplayed.^[6] Still, President Kennedy proposed preventive action but it was decided against by the U.S. government as it was "likely to be viewed as provocative and dangerous and will play into the hands of efforts by [Beijing] to picture U.S. hostility to Communist China as the source of tensions and the principal threat to the peace in Asia."^[12] By early 1964, from surveillance of activity around the Lop Nur site, it was clear that a test would be imminent.

The next step for China was to develop the mode of delivery of a nuclear payload. Just eight months after the 596 test, a deliverable nuclear bomb was successfully dropped from a bomber and detonated. A year later, medium range missiles were fitted with nuclear warheads. The Lop Nur test site was used to develop more sophisticated nuclear weapons such as the hydrogen bomb, multi-stage thermonuclear devices, and Intercontinental Ballistic Missiles (ICBM).^[5] While China's nuclear arsenal was modest compared to that of the Soviet Union and the United States,^[13] the presence of another nuclear power in Asia raised the issue of uncontrolled proliferation. The USA took measures to forestall the independent development of nuclear capabilities in more Asian nations, most immediately with India.^[14] Top U.S. officials began open talks of non-proliferation with the Soviet Union soon after the 596 test to offset the possibility of a nuclear China propelling a larger and more unpredictable global arms race.^[15]

Soviet Union

Chinese nuclear capacity prompted the Soviet Union to sign the 1968 Treaty on the Non-Proliferation of Nuclear Weapons with the United States as well as China.^[16]

Japan

While the 1964 Summer Olympics which opened on 10 October was already underway in Tokyo, China conducted the atomic bomb test six days into the competition, prompting hysterical and immediate concerns of radiation fallout in Japan as it is relatively close to mainland China.^[17]