The specter of nuclear weapons continues to haunt our world. Since the 1940s there have been several attempts to control the manufacture and use of nuclear weapons. Currently two major global arms control efforts are being pursued. The first is the Comprehensive Test Ban Treaty (CTBT), which is under negotiation at the United Nations Conference on Disarmament in Geneva. The aim of this treaty is to prohibit nuclear tests and thus inhibit countries from developing qualitatively new weapons. The second is a Fissile Material Production Cutoff Convention. This would prohibit countries from production of fissile materials for use in nuclear weapons. The aim of this treaty is to prevent countries from increasing the number of nuclear weapons in their arsenal.
All nuclear weapons require fissionable raw material - highly enriched uranium (HEU) or plutonium. Since neither of these is found in nature, extensive processing facilities are needed in order to produce them. Thus, a natural route to cap the world's nuclear arsenal is to control or stop the production of these materials for use in weapons. Control strategies, however, are complicated by the fact that uranium and plutonium can also be used for non-weapons purposes, especially as fuel for nuclear reactors. As a result, the approach adopted by the international community has been to allow the production and use of fissile material but to monitor (or "safeguard") its use to verify that it is not diverted to making nuclear weapons. This strategy is applied to those countries that possess and use fissile material among all the countries that have signed the Nuclear Non-Proliferation Treaty (NPT) as non-weapon states.
A production cutoff was first proposed by President Eisenhower in 1956. Since it would have frozen the Soviet nuclear arsenal into a quantitatively lower level, the USSR rejected this proposal. During the negotiation of the Non-Proliferation Treaty in 1967, India argued that the treaty should contain "universal, objective and non-discriminatory'' controls on, among other things, "the production of weapons grade fissile material.'' In 1989, President Gorbachev agreed to a cutoff in production, but the Bush administration in the U.S. was opposed to it. The recent interest in the cutoff arises from the Clinton administration's review of U.S. nonproliferation policy in September 1993 and its consequent proposal for a "multilateral convention prohibiting the production of highly enriched uranium or plutonium for nuclear explosive purposes or outside of international safeguards." Three months later, the U.N. General Assembly passed resolution 48/75 which ''calls upon all States to demonstrate their commitment to the objectives of a non-discriminatory, multilateral and internationally and effectively verifiable treaty banning the production of fissile material for nuclear weapons or other nuclear explosive devices.''
A cutoff treaty would allow states which already have stocks of unsafeguarded fissile material to maintain them outside of international safeguards, but would allow the future production of fissile material only if the material is safeguarded to ensure that it is not used in weapons. While the convention will be open to all countries for signature, the states that have already signed the NPT as non-nuclear weapon states are already subject to all the provisions of a fissile cutoff. Thus the primary goal of the convention will be to attain the signatures of the five declared nuclear weapon states (China, France, Russia, the United Kingdom, and the U.S.) and the three undeclared states (India, Israel, and Pakistan).
A fissile cutoff would reduce the discriminatory nature of the existing non-proliferation regime by stopping the nuclear weapon and undeclared states from being the exclusive producers of unsafeguarded fissile materials. It seems likely, however, that a fissile cutoff convention will not seek to include existing stocks. Thus, even though the cutoff would be non-discriminatory in how it applies to different countries, it would have highly unequal effects on the different signatories. For example, the U.S. and Russia have large existing stocks, whereas other countries have much smaller amounts. This is an important consideration for countries like China, India, and Pakistan. The only way to eliminate completely this discriminatory nature would be for countries to also combine the cutoff treaty with arrangements to maintain the pressure for disarmament.
A production cutoff would have few immediate implications for the U.S. and Russia. Both countries have huge stocks of fissile material and have by and large stopped producing further amounts. Since the nuclear arsenals of both countries are being reduced under the START treaty, large quantities of HEU and plutonium are being reclaimed and thus neither will have to draw on their existing stockpiles. In July 1992, President Bush announced a unilateral ban on the production of fissile material for weapons. The Soviet Union stopped manufacture of HEU for weapons in 1987; it is unclear if it is continuing production of HEU for other purposes. Russia still continues to produce plutonium and it is unwilling to shut these plants down since they supply heat for domestic purposes. In March 1994, the U.S. pledged to help investigate ways to replace the power from these plants as quickly as possible.
Britain is not believed to have produced weapons grade uranium since 1963, in part because it was able to acquire HEU from the U.S. It is also not believed to be producing any plutonium currently. However, since its military stocks of fissile material are relatively small, a production cutoff would place reasonably strict limits on the size of its future arsenal.
France is not currently believed to be producing fissile material for weapons. However, France does not make a clear distinction between civil and military materials and has reportedly used plutonium produced in power reactors to make nuclear weapons. Given the size of its stockpile, a cutoff would have little immediate impact on its nuclear-weapons program.
China is reported to have stopped producing HEU and plutonium for weapons. Because there is much uncertainty about the size of its nuclear arsenal and its past production, the size of its military stockpiles is unknown and thus the implications of a cutoff are not clear. The Chinese defense strategy is also not well understood and this is a further source of uncertainty.
It is the undeclared states (India, Israel, and Pakistan) for which there is much uncertainty in the implications of a cutoff. Since these are believed to have relatively small stocks, a cutoff would affect them most dramatically.
For a cutoff treaty to be credible it needs to be verified. This is complicated by the fact that many previously unsafeguarded facilities will continue to operate under a cutoff. These could be civil nuclear energy facilities, facilities for the production of HEU for naval reactors and production of isotopes for industrial and medical purposes. Apart from these legitimate activities, there could also be included processing of plutonium and uranium, maintenance of nuclear weapons stockpiles and research and development of nuclear weapons.
The core set of facilities targeted for verification would include those which produce or have, in the past, produced, HEU or plutonium for weapons. This could be widened to include operating or shut-down plutonium production reactors as well as civil nuclear facilities. The scale of a verification scheme that includes all these can be realized by noting that the U.S. alone has about 300 facilities that might be subjected to safeguards. An even broader system could include measures to detect clandestine fissile production.
The monitoring of sites where permitted activities relating to nuclear weapons and production of prohibited materials are carried out could pose the most difficulties for verification under a cutoff. This is because the inspected nations may obviously desire to protect classified information from inspectors. Some of the methods suggested to take care of these problems are remote sensing from satellites and aircraft, environmental sampling of air, water, or soil in the vicinity of the site, and independent verifications of material accounting data.
There is general agreement that the principal verifying agent of a multilateral cutoff treaty should be the International Atomic Energy Agency (IAEA) which already conducts such verification for all non-weapons signatories of the NPT. Moreover, the IAEA has significant experience applying safeguards in a variety of situations. This would require an increase in the workload, and the budget of the IAEA. It may also take time to train additional IAEA inspectors and otherwise prepare to fully implement safeguards. As a result, the convention could specify that the verification provisions be phased in over a period of a few years, beginning with the core facilities.
A fissile cutoff is central to the future of nuclear arms control and provides the only way to cap nuclear arsenals. This is, of course, only the first step, since a cutoff treaty would still leave states with unsafeguarded material that can be used for weapons. However this is a necessary first step, and, in view of the dangers of stockpiling and proliferation, it is urgent .