Chemical warfare: the cloud of doubt

The Reagan administration has charged that the Soviet Union is manufacturing biological warfare agents and has either used chemical and biological weapons or provided them to allies, who have used them in Afghanistan and Southeast Asia. The possibility that the charge is correct has raised serious questions about the effectiveness of arms control measures and our ability to be certain that other countries are keeping their arms control promises.

Two multilateral treaties cover chemical and biological weapons. In the aftermath of the use of poisonous gas in World War I, the 1925 Geneva Protocol outlawed the ''use in war of asphyxiating, poisonous or other gases, and of bacteriological methods of warfare.'' The 1974 Biological Weapons Convention was more comprehensive, banning the development, production, and stockpiling of ''bacteriological (biological) and toxin weapons,'' and ordering the destruction of existing stocks of the weapons. The Soviet Union signed both documents.

Since 1979 the US government has been suspicious about an apparent anthrax epidemic in the Soviet Siberian town of Sverdlovsk. If a factory which has been identified in Sverdlovsk is producing anthrax bacteria in large quantities as suspected, the Soviets could be in violation of the 1974 treaty.

Reports of refugees and military defectors, medical examination of victims, and analysis of a very few plant and water samples have also pointed to the recent use of chemicals in several countries. The substances found include poisonous gases in Afghanistan, and the newly-identified, deadly, trichothecene mycotoxin in Vietnam, Laos, and Kampuchea.

The evidence is all what a lawyer would consider circumstantial. But in each instance where chemical attacks have been reported the Soviet Union or its allies have become bogged down in a war of attrition against guerrilla forces, in a geographically inaccessible area. Chemical warfare is an attractive military option in such a situation. And the Soviet Union is known to regard chemical combat as an important element of warfare. Regular Soviet ground forces include chemical corps, and these units, with their distinctive decontamination gear, have been observed in Afghanistan.

The question of whether the USSR is violating the treaties is profoundly important, for more than humanitarian reasons. If the Soviets are testing and refining new substances and means of conducting chemical warfare, the United States and other countries must give more serious consideration than before to military countermeasures. If they are violating the two treaties, doubt is cast upon Soviet intent in the dozen other arms limitation treaties to which it has been a party in the nuclear age. And the fact that controversy still rages about whether or not a breach has occurred, after two years of debate, is a distressing reminder that means for verification of compliance with the agreements must be improved, perhaps including an on-site inspection.

The Soviets deserve to either be proved guilty or exonerated of the charges, as quickly as possible. If the Reagan administration succeeds, through its public campaign, in stopping the chemical attacks, that would serve a moral good. But if responsibility is left unclear, the larger questions about Soviet capabilities, intentions in upholding international agreements and verification procedures will also go unresolved.

The trouble is, any allegations the US makes about Soviet chemical warfare are assumed by the rest of the world to be politically motivated. It is left to the press and private and international organizations, therefore, to mount independent efforts to weigh the existing information and collect new evidence, until the mystery of who, if anyone, is conducting chemical warfare is solved.

If the Soviet Union is innocent, it would behoove that country to assist efforts to investigate the reports of chemical attacks, rather than block them as it has done to date. Because as long as the cloud of doubt upon the Soviet Union remains, the US is liable to avoid further arms agreements - and to steadily increase its own ability to fight chemical war.