As the Soviet Union gradually disintegrates, anxiety has increased in the West that Moscow will not be able to maintain its command and control over the country's arsenal of 30,000 nuclear weapons. Nightmare scenarios abound of nuclear terrorism and sabotage, or of widespread proliferation with 15 renegade republics each possessing nuclear weapons.
Many in the United States argue that it is in the West's interest to support Mikhail S. Gorbachev in his struggle with the republics -- that only his strong leadership atop a muscular central government can contain the civil disorder and nuclear instability that a break-up of the U.S.S.R. would bring.
The argument fails to recognize that Mr. Gorbachev has dissipated much of his domestic credibility by his unwillingness to implement substantive economic reforms, and that recent agreements between the republic governments and Moscow point to a significant devolution of power. More important, this policy incorrectly assumes that increased autonomy or independence for the country's republics will be destabilizing and will lead to an unacceptable risk of nuclear confrontation.
In fact, the threat of ''proliferation by disintegration,'' never very great, has diminished. Under the 1988 intermediate-nuclear-forces treaty, the Soviet Union will eliminate over 800 nuclear missiles. When the treaty on strategic systems is final, the stocks of the most powerful Soviet intercontinental ballistic missile, the SS-18, will be halved. Soviet nuclear weapons are now based in fewer than half of the country's 15 republics; the majority remain in the Russian republic.
It is virtually impossible for the republics to gain control over any nuclear weapons based on their territory. The weapons are guarded by highly trained and rigorously screened KGB agents. These guard units are composed solely of ethnic Russians, making sabotage by an ''insider'' sympathetic to a terrorist or nationalist cause unlikely. Even if access to the weapons could be gained, it would be impossible to detonate the nuclear device without the firing codes that are retained off-base by the political leadership.
On a political level, if there is one issue in the republics that does not draw support from politicians and voters, it is nuclear weapons and nuclear-energy production. The disaster at Chernobyl in April 1986, the ensuing human tragedy and the failure of the central government to inform and protect the affected civilian population have created anti-nuclear near-hysteria throughout Byelorussia, the Ukraine and parts of Russia.
The Ukraine's declaration of sovereignty calls for the republic not to accept, produce or purchase nuclear weapons; Byelorussia's provides for the republic to become a nuclear-free zone. Recent statements from the leadership of Kazakhstan, an area that for years was used by Moscow as a testing ground for nuclear weapons, indicate that the republic would not eagerly embrace its own nuclear stockpile even if it had the chance.
It is from the republics that one hears the most vocal calls for scaling down the country's nuclear- energy program. According to a pro-nuclear article in Izvestia, written on the eve of the anniversary of Chernobyl, recently adopted regulatory measures addressing the tragedy by the Ukraine and Byelorussia so burden the Soviet nuclear industry that it could be ''put on the edge of bankruptcy.'' During the past four years, in large measure as a result of opposition and pressure at the republic level, construction, work and expansion projects have been halted at 39 nuclear plants around the Soviet Union, and 1.9 billion rubles designated for the nuclear industry have been frozen.
The republics' demands for autonomy or independence are not the root cause of instability in the Soviet Union; rather, it is Moscow's 70-year mismanagement of the so-called nationalities question. Only the naive could have believed that increased freedom and a move toward a market economy could have resulted in anything but an explosion of separatist movements and nationalist grievances.
Yet, rather than wanting to use nuclear weapons against Moscow, the republics want to be left alone. Consequently, they are concentrating on how to discard the Soviet legacy of economic mismanagement and inefficiency.
That the transition from a centralized authoritarian regime to a confederation of nine or so republics will be accompanied by upheaval and some violence is probably inevitable. But it will not result in nuclear catastrophe. The greatest insurance for stability is a decentralized, democratic, market-oriented system, which will minimize the possibility of inter-republic conflicts.
John Hewko is an American attorney working in Moscow and Kiev. Mitchell Reiss is an attorney in Washington. They wrote this commentary for the Christian Science Monitor.