Stemming nuclear proliferation

Late this month a British defense journal reported that Ayatollah Khomeini's Iranian regime was making a nuclear bomb, to be ready within two years. Although that schedule seems unlikely to be met, the war with Iraq could well be viewed by Khomeini as ample motivation for nuclear adventurism, despite Iran's signature on the 1968 Non-Proliferation Treaty (NPT).

Set against other developments, such as recent claims by Argentine and Pakistani scientists that they can now enrich uranium to the grade required for nuclear weapons, the lesson is clear. Our decades-long fear of nuclear weapons spreading to more and more countries is nearing reality. It is time to reform the worldwide controls meant to prevent this spread.

We should also recall that nuclear proliferation occurs in two dimensions. Horizontal proliferation is the acquisition of nuclear weapons by additional countries, while vertical proliferation refers to expansion in the sizes or capabilities of existing nuclear arsenals.

At present, the vertical dimension is actually the most dangerous. Negotiations between the superpowers are suspended, at a time when destabilizing weapons systems are under development or entering service. This drift of events is doubly disturbing in light of recent research showing that the global aftermath of nuclear war could be much worse than previously thought.

While the superpowers are preoccupied with their competition, it is becoming progressively easier for nations or terrorist groups to join the nuclear club. Nuclear power programs are yielding both a growing pool of skilled technicians and a large inventory of fissile materials, especially plutonium. Delivery systems, such as aircraft and missiles, are available to many countries.

An international regime of proliferation control does exist, consisting of the NPT and the inspection powers of the International Atomic Energy Agency. Yet , this regime is very weak. Many nations have not signed the NPT, and the IAEA has limited powers over those nations that have signed. Moreover, the treaty effectively expires in 1995.

The NPT's weakness owes much to its basic inequity. Non-nuclear signatories are expected to forgo nuclear weapons in return for a vague promise by the nuclear-armed parties to ''pursue negotiations in good faith'' to end their arms race. Events have shown this promise to be empty. An illustration is President Carter's 1978 attempt to persuade the Indian government to sign the NPT, on the grounds that various US-Soviet arms talks were nearing agreement. Six years later, none of those talks have led to a ratified treaty.

A route to controlling the perilous drift of events is provided by ''proliferation reform.'' Under this concept, both horizontal and vertical proliferation would be restrained by a uniform, equitable, international regime. Tightened restrictions, applicable equally to nuclear-armed and other countries, would be placed on commerce in nuclear materials and technology, and the IAEA's budget and inspection powers would be greatly increased. Nuclear-armed countries , in order to join this system, would be obliged to separate completely their commercial nuclear operations from their military nuclear activities. Finally, the nuclear powers would be required to pledge specific arms control actions, to be achieved by specific dates.

The United States has much to gain from this arrangement. Proliferation reform could restrain horizontal proliferation, while, at the same time, it applied additional pressure on the Soviets to adhere to arms agreements. On their part, the Soviets have as much reason to curb both dimensions of proliferation as we do. Likewise, other nations would benefit from a regime that reduces the overarching threat of a superpower conflict at the same time as it restrains neighboring nations and terrorist groups. Non-signatories to the NPT would feel great pressure to participate in this new system.

Every five years an international conference is held to review the status of the NPT. At the next such conference, next year, the US could take the lead in proposing reform measures: A foundation could be laid for a more comprehensive and powerful treaty to replace the NPT after its expiration in 1995. If we fail to take this lead, other nations may feel obliged to do so.

In 1946, the US put the Baruch Plan before the fledgling United Nations, proposing international controls that would have suffocated the nuclear arms race at birth. The evident failure of this bold, though ill-conceived, plan should not blind us to the present need to move toward a firm and fair system of international nuclear arms control. Our future without such a system looks insecure indeed.