THERE'S no better bargaining chip than the threat of a nuclear missile. North Korea got the US's attention this year when it appeared to be producing bomb-grade plutonium in quantity. The two struck a deal that, for now, keeps the unpredictable Asian regime in line.
Less totalitarian countries, however, are using a more pedestrian way to gain the ear of nations with nuclear weapons. They see as their best bargaining chip a conference here next April, at which the 25-year-old Nuclear Non-Proliferation Treaty (NPT) will come up for extension.
Most acknowledged members of the nuclear-weapons club - the United States, Russia, France, and Britain - want to vote for the treaty to stay in effect permanently and unconditionally. (China so far has kept mum.)
But settling the issue would snatch from nonnuclear nations their only leverage against the nuclear states. They want the treaty to be renewed for a limited period, since that would eventually force the more powerful nuclear states back to the negotiating table.
The NPT, which now has 167 signators including Ukraine, is the chief legal barrier to the global spread of nuclear weapons. Widely regarded as a cold-war success story, the treaty obliges those without nuclear weapons not to get them and those who already have them to try to stop the nuclear arms race. The NPT preamble expresses the parties' joint determination to end the testing and manufacture of nuclear weapons and to liquidate existing stockpiles.
Experts expect the NPT to be extended next year. But for how long and with what backing? Though any decision requires a majority vote of 84, all parties would prefer to act by consensus.
As recently as a few months ago, the US thought it had ample support for its position. Yet only 67 nations - less than half of the NPT's signators - formally support the move.
``I fear the battle lines are being drawn already,'' Jayantha Dhanapala of Sri Lanka remarked at a recent seminar on the subject in Tarrytown, N.Y. He is the former head of the United Nations Institute for Disarmament Research and will chair the April NPT conference.
Generally the nuclear powers are supported in their stance by other European nations, Australia, and Canada.
Many of the less-developed nonnuclear nations, sometimes termed the economic ``south,'' want to see limits on the treaty extension.
The ``solidarity of the south is not merely a slogan,'' Mr. Dhanapala noted. He warns those supporting a permanent extension of the treaty against ``counting their chickens before they are hatched.''
Unless the nuclear powers leap to convince skeptics they are doing their best to meet their treaty commitments, the resulting fireworks at the NPT conference could make the recent controversial UN conference on population in Cairo ``look like a walk in the park,'' says Joseph Cirincione, a nuclear expert at the Henry L. Stimson Center in Washington. ``There are determined opponents to the treaty that have already started maneuvering to wreck the conference.''
``Nobody really knows what's going to happen because everybody is engaged in a tug of war,'' agrees a UN official.
The tug of war could go in many directions. Currently the NPT has only 17 fewer members than the 184-member UN itself, which takes in Palau as its 185th member this month. Argentina is expected to sign the NPT before the spring conference, though Brazil is not likely to sign on until 1996. Experts say Israel, India, and Pakistan - widely considered nuclear-weapons states though they do not admit it - may never sign on.
One encouraging sign, however, is that more countries are signing nuclear-free zone regional pacts. Latin America has a strong area accord, and Africa is expected to have one ready for signature soon.
Heeding the call
By most estimates, the US and its allies probably could get the required majority for their plan. Yet experts say there are serious drawbacks if half the NPT signers go home unhappy. The treaty's authority, for instance, could be seriously undermined. North Korea, if again chastised for NPT noncompliance, might be less inclined to suspend its withdrawal from the treaty and to make a deal with the US next time around.
Some nonnuclear states might choose to withdraw from a treaty that allows no further opportunity for review or renewal, so that progress toward disarmament can at least be assessed. Many such states now favor a series of fixed short-term NPT renewals for that reason.
Many experts say the US and the other nuclear nations are largely responsible for their own dilemma.
The nations not belonging to the NPT have been allowed to ``define the debate,'' peeling away votes that the US thought it had, says Ivo Daalder, an arms-control expert at the University of Maryland. ``That's why it's important [for the US] to start making counterarguments and major statements at high levels,'' he says. ``The administration, for instance, has not said whether it supports nuclear disarmament as an ultimate goal.''
Much of the strongest criticism of the nuclear-weapons states surfaced last fall at the third preparatory meeting for the NPT conference in Geneva (a fourth will be held in New York in late January) and in the regular meetings of the UN General Assembly's First Committee, known as the disarmament committee.
Japan, which supports the US position for an indefinite NPT extension, but not necessarily an unconditional one, for the first time submitted a resolution in the General Assembly committee calling on nuclear states to aim for eliminating all nuclear weapons.
``The obligations of the nonnuclear powers and the nuclear powers must be kept in balance...,'' is the diplomatic explanation of Hirashi Owada, Japan's ambassador to the UN.
All mention of specific steps to be taken by nuclear powers toward disarmament was deleted from an earlier version of the resolution, apparently in response to US pressure. Even so, the US, Britain, and France abstained on that vote and opposed several similar measures. ``I think the nuclear powers sent the wrong message by being so negative,'' says a Western disarmament expert closely following the issue. The formal Assembly vote on all resolutions, essentially a rubber stamp of the committee vote, is to take place Dec. 15.
Washington objects to any suggestion that the treaty obliges the US to meet any set conditions by any set time. Yet as William Epstein, who represented the UN secretary general at the NPT negotiations, writes in the current issue of the Bulletin of Atomic Scientists: ``In fact there are linkages, and they are rooted in the language of the treaty.''
Nonproliferation has its price
What confidence-building measures would help persuade the nonnuclear weapons states to extend the NPT permanently?
* Most nonnuclear weapons states want to see clear progress on the proposed Comprehensive Test Ban treaty (CTB) that would ban tests underground in addition to other locations.
Ali Alatas, foreign minister of Indonesia, which is currently chairman of the nonaligned group, says the importance of the treaty is impossible to overemphasize. Though opposed until 1993, the US now favors the treaty. Still, neither France nor China (the only nation still doing underground testing) appears ready to sign a CTB. Some experts say the US must take a stronger leadership role on the treaty. One possibility, they say, is to complete and make public the draft text by April and extract firm promises of a date for the actual treaty signing.
Wooing the delinquents
Also, a test-ban treaty could encourage nations that do not belong to the NPT to play at least some role in controlling nuclear proliferation. Though Israel, India, and Pakistan have not signed the NPT, Adam Scheinman, a nuclear analyst with the Lawyers Alliance for World Security in Washington, notes that all three nations have shown a clear interest in becoming original signers of a comprehensive nuclear test ban accord.
* Nonnuclear states also want to see the five nuclear states try harder to cut back on nuclear weapons and their production. Ukraine's move to sign the NPT Dec. 5 allowed Russia and the US to begin implementing the first Strategic Arms Reduction Treaty.
Most experts think the two cold-war rivals can make a good case for having done about as much they can in this area. Yet both still have thousands of nuclear weapons. Until the totals come down further, experts say, Britain, France, and China, each of which has nuclear weapons numbering only in the hundreds, have little incentive to reduce stocks.
* Lastly, states that lack nuclear weapons want stronger security guarantees from the five nuclear powers. The most likely format is a legally binding resolution from the Security Council where the five nuclear powers sit as the five permanent members. Some such assurance is likely to be passed in January at a foreign ministry summit of the Council. Each of the five has pledged not to attack other NPT signers. The question lies in one key US caveat: that no attack will occur against another NPT member unless that member is allied with a state that uses nuclear weapons or has them placed in its territory. The exception was originally aimed at Warsaw Pact members. Nonaligned nations are now unlikely to be satisfied with it.
Many experts say the primary leadership on each of these issues must come from the US. ``The White House doesn't really think it has a problem here, and it hasn't been paying attention,'' Mr. Cirincione insists.
He says the NPT conference could well break up without really deciding what to do. One possibility, experts say, is a recess until more solid progress is made on the test-ban treaty. As a backup position, the White House is currently exploring the legality of a possible series of rolling extensions for the NPT.
By most assessments, the nuclear threat has greatly diminished with the collapse of the Soviet Union and the end of the cold war. Yet use of nuclear weapons by terrorists or renegade states in or out of the NPT remains a constant concern. The treaty has proved a valuable tool for gaining better compliance in both North Korea and Iraq. Before the NPT came into force in 1970, acquiring nuclear weapons was often seen as a matter of national pride. Now any programs to acquire or produce such weapons exist in secret if at all.