Since its inception, China's nuclear weapon program has relied on a mixture of foreign assistance, indigenous know-how and espionage to steadily develop and modernize its nuclear arsenal from its first implosion device to the development of tactical nuclear weapons in the 1980s. As a result of this program, China is assessed to have at least six different types of nuclear weapons: a 15-40 kiloton (kt) fission bomb; a 20 kt missile warhead; a 3 megaton (mt) thermonuclear missile warhead; a 3 mt thermonuclear gravity bomb; a 4-5 mt missile warhead; and a 200-300 kt missile warhead. China is also estimated to posses some 150 tactical nuclear weapons.

In its 2005 Annual Report to Congress on the Military Power of the People's Republic of China, the U.S. Department of Defense noted that "China is qualitatively and quantitatively improving its strategic missile force," which could "provide a credible, survivable nuclear deterrent and counterstrike capability." The report identifies "approximately twenty silo-based, liquid-propellant CSS-4 ICBMs" as constituting China's "primary nuclear deterrent" capable of hitting targets in the continental United States.

History

China's efforts to develop a nuclear weapons program came in response to nuclear threats by the United States. In July 1950, at the very beginning of the Korean War, President Truman ordered 10 nuclear configured B-29s to the Pacific, and "he warned China that the U.S. would take 'whatever steps are necessary' to stop Chinese intervention and that the use of nuclear weapons 'had been under active consideration.'" In 1952, President-elect Eisenhower publicly hinted that he would authorize the use of nuclear weapons against China if the Korean War armistice talks continued to stagnate. In 1954, the commander of the U.S. Strategic Air Command General Curtis LeMay stated his support for the use of nuclear weapons if China resumed fighting in Korea. LeMay stated, "There are no suitable strategic air targets in Korea. However, I would drop a few bombs in proper places like China, Manchuria and Southeastern Russia. In those 'poker games,' such as Korea and Indo-China, we...have never raised the ante--we have always just called the bet. We ought to try raising sometime." Finally, in January 1955, U.S. Navy Admiral Radford also publicly advocated the use of nuclear weapons if China invaded South Korea.

These threats prompted the Chinese to begin developing nuclear weapons in the winter of 1954-55. The Third Ministry of Machinery Building (renamed the Second Ministry of Machinery Building in 1957 and then in 1982, the Ministry of Nuclear Industry) was then established in 1956. With Soviet assistance, nuclear research began at the Institute of Physics and Atomic Energy in Beijing, and a gaseous diffusion uranium enrichment plant in Lanzhou was constructed to produce weapons-grade uranium. On 15 October 1957, the U.S.S.R. agreed to provide China with a sample atomic bomb and manufacturing data. From 1955 to 1959, approximately 260 Chinese nuclear scientists and engineers went to the Soviet Union, while roughly the same number of Soviet nuclear expert traveled to China to work in its nuclear industry. However, by 1959 the rift between the Soviet Union and China had become so great that one year later in 1960 the Soviet Union discontinued all assistance to China. After 1960, China was forced to go it alone.

China successfully tested its first atomic bomb on 16 October 1964--with highly enriched uranium produced at the Lanzhou facility--and just 32 months later on 17 June 1967, China tested its first thermonuclear device. This achievement is remarkable in that the time-span between the two events is substantially less than the other nuclear powers. By point of comparison, 86 months passed between the United States' first atomic test and its first hydrogen bomb test; for the U.S.S.R. it was 75 months; for the U.K. 66 months; and for France 105 months.

On 27 October 1966, China launched a Dong Feng-2 (DF-2) medium range ballistic missile (MRBM) from the Shuangchengzi missile test site in Gansu province, which struck its target in the Lop Nur test site. The missile carried a 12 kiloton nuclear warhead, marking the only time that a country has tested a nuclear warhead on a ballistic missile over populated areas.

Starting in the mid-1960s, China adopted a policy known as the "Third Line," which was an effort to construct redundant nuclear production facilities in the interior of China to make them less vulnerable to attack. "Third Line" facilities include: a gaseous diffusion uranium enrichment facility at Heping; a plutonium production reactor and extraction facility at Guangyuan; the Nuclear Fuel Component Plant at Yibin; and the nuclear weapon design facility at Mianyang. The "Third Line" was conducted during China's Third (1966-70) and Fourth (1971-1975) Five-Year Economic Plans.

Nuclear Modernization during the 1980s and Beyond

China's nuclear tests in the late-1980s and 1990s were geared toward further modernizing its nuclear forces. Although China officially declared in 1994 that these tests were for improving safety features on existing warheads, they were also likely intended for the development of new, smaller warheads for China's next-generation solid-fuel ICBMs (e.g. DF-31 and DF-31A) and possibly to develop a multiple warhead (MRV or MIRV) capability as well. Some speculate that China wanted to delay an international test ban until it could complete its latest round of tests and only announced a testing moratorium after all the tests necessary for the next phase of nuclear modernization were completed. China's last test was on 29 July 1996 and less than two months later on 24 September 1996, Beijing signed the Comprehensive Test Ban Treaty (CTBT).

China's 1996 signature to the CTBT was the latest in a serious of policy shifts on nuclear nonproliferation. In fact, it was during the 1980s that China's position on nuclear proliferation first started to change. During the 1980's, Beijing continued to criticize the Nuclear Nonproliferation Treaty (NPT) as an imbalanced, discriminatory treaty, but also indicated that it accepted in principle the norm of nuclear nonproliferation. In 1984, China joined the IAEA and agreed to place all of its exports under international safeguards; that same year a senior Chinese official during a trip to the U.S. provided Washington with verbal assurances that China did not advocate or encourage nuclear proliferation. In 1990, though still not a member of the NPT, China attended the fourth NPT review conference and, though it criticized the treaty for not banning the deployment of nuclear weapons outside national territories and for not including concrete provisions for general nuclear disarmament, China also stated that the treaty had had a positive impact and contributed to the maintenance of world peace and stability. In August 1991, shortly after France acceded to the NPT, China also declared its intention to join, though it again expressed its reservations about the treaty's discriminatory nature.

China formally acceded to the NPT in March 1992 as a nuclear weapon state--the last nuclear weapon state to do so. In its statement of accession, the Chinese government called on all nuclear powers to issue unconditional no-first-use pledges, to issue negative and positive security assurances to the non-nuclear weapon states, to support the development of nuclear weapons free zones, to withdraw all nuclear weapons deployed outside national territories, and to halt the arms race in outer space.

Since its accession, China has praised the NPT's role in preventing the proliferation of nuclear weapons, and China supported the decision to indefinitely extend the NPT at the 1995 Review and Extension Conference. However, China has continued to state that it views nonproliferation not as an end in itself, but rather as a means to the ultimate objective of the complete prohibition and thorough destruction of nuclear weapons. In addition, China was embroiled in nuclear proliferation scandals throughout the late 1980's and early 1990's, particularly with respect to its sale of ring magnets to Pakistan in 1994. Most recently, it was learned that China provided Pakistan with a nuclear bomb design (used in China's October 1966 nuclear test), and that Pakistani nuclear scientist A.Q. Khan provided China with centrifuge technology and data for uranium enrichment.

In the late 1990s, U.S. attention focused on the role of Chinese espionage in assisting China's nuclear weapon development. The U.S. Congress formed a Select Committee on U.S. National Security and Military-Commercial Concerns with China (aka the Cox Committee). According to the Cox Committee Report, suspicion of China's nuclear espionage started after the U.S. government realized that information derived from Chinese tests in 1992-1996 were similar to U.S. nuclear designs. This similarity combined with other information derived from classified sources led the Cox Committee to claim that China had stolen several bomb designs, including the U.S.'s most advanced W-88 design and a design for an enhanced radiation weapon (neutron bomb). Yet, the Cox Report has been severely criticized by both experts and officials in the United States as a political document that has several technical inaccuracies.

The Future of China's Nuclear Modernization

There is much speculation that China's nuclear modernization program may be geared toward developing the capacity to move from a strategy of minimum deterrence to one of limited deterrence. "Limited deterrence" entails the capability to deter conventional, theater, and strategic nuclear war, and to control escalation in the event of a nuclear confrontation. Under a "limited deterrence" doctrine, China would need to target nuclear forces in addition to cities, which would require expanded deployments. However, such a limited deterrence capability may still be a long way off. According to Alastair Johnston, "It is fairly safe to say that Chinese capabilities come nowhere near the level required by the concept of limited deterrence."

Regardless of the ultimate intent of these activities, through these modernization efforts, China continues to develop faster, sturdier, and more accurate missiles that may carry smaller second-generation nuclear warheads, multiple reentry-vehicles (MRVs) and various penetration aids. The deployment of the DF-31, combined with the introduction of the JL-2 SLBM and Type 094 SSBN submarine, would significantly enhance China's deterrence capabilities, yet they would also increase the risk of unauthorized or accidental launches.

So, why is China strengthening its nuclear arsenal? Three primary explanations exist. First, China may simply wish to update its aging weapons systems and replace them with more modern systems. Second, China may be seeking a new fleet of ballistic missiles to increase the survivability of its nuclear deterrent. As other countries (particularly the United States) continue to increase their military capabilities, China may feel more vulnerable. From Desert Storm through the 2003 war in Iraq, the United States has continuously demonstrated its ability to use conventional forces to destroy fixed targets with tremendous accuracy. U.S. efforts to develop a ballistic missile defense system also threaten the deterrence capability of China's aging nuclear forces. China's leaders may fear that their older, immobile nuclear forces are vulnerable or ineffective as a deterrent, and should be replaced by newer, road-mobile nuclear forces and ICBMs such as the DF-31 and DF-31A missiles. Finally, China's efforts to increase its nuclear capabilities may indicate an important, yet undeclared, shift toward a more assertive nuclear policy. Proponents of this explanation argue that "More Chinese missiles might signal a possible shift from a retaliatory counter value posture to an offensive counterforce posture, particularly if accompanied by necessary improvements in accuracy. According to Paul Godwin, a sufficient number of weapons could permit China for the first time to attempt intrawar escalation control, since Beijing would retain enough forces to respond at a higher level if the aggressor chooses to escalate a nuclear exchange."

Sources:
"Statement of the Government of the People's Republic of China," 16 October 1964, http://www.nti.org/db/china/engdocs/nucsta64.htm;
Natural Resource Defense Council, "Chinese Nuclear Forces, 2002," http://www.nrdc.org/nuclear/nudb/datab17.asp
U.S. Department of Defense, "Annual Report to Congress on the Military Power of the People's Republic of China," August 2005, www.defenselink.mil
Yan Kong, "China's Nuclear Bureaucracy," Jane's Intelligence Review, July 1993
John Wilson Lewis and Xue Litai, China Builds the Bomb, (Stanford: Stanford University Press), 1988
Phillip Saunders and Jing-Dong Yuan, "China's Strategic Force Modernization: Three Scenarios and Their Implications for the United States," Center for Nonproliferation Studies, Monterey Institute of International Studies, 2003
National Intelligence Council, "Foreign Missile Developments and the Ballistic Missile Threat Through 2015," December 2001
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Bates Gill, James Mulvenon, Mark Stokes, "The Chinese Second Artillery Corps: Transition to Credible Deterrence," in The People's Liberation Army as an Organization: Reference Volume v1.0;" Ed: James C. Mulvenon, Andrew N.D. Yang, 2001. Page 550, 553
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Robert S. Norris, Andrew S. Burrows and Richard W. Fieldhouse, British, French, and Chinese Nuclear Weapons, Boulder: Westview Press. 1994. pp. 350-352, 358
Bates Gill and Taeho Kim, China's Arms Acquisitions from Abroad: A Quest For 'Superb and Secret Weapons', Oxford: Oxford University Press. 1995. pp. 28-30; pp. 14, 18, 32
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	Updated January 2006