The “Yellow Rain” Controversy: Lessons for Arms Control Compliance

During a speech to the Berlin Press Association on September 13, 1981, U.S. Secretary of State Alexander Haig made a dramatic allegation. He accused the Soviet Union of supplying mycotoxins— poisonous compounds synthesized by fungi—to its Vietnamese and Laotian Communist allies for military use against resistance forces in Laos and Cambodia (Kampuchea), and of employing the same agents in combat operations in Afghanistan. “For some time now,” Haig said, the international community has been alarmed by continuing reports that the Soviet Union and its allies have been using lethal chemical weapons in Laos, Kampuchea, and Afghanistan.... We have now found physical evidence from Southeast Asia which has been analyzed and found to contain abnormally high levels of three potent mycotoxins—poisonous substances not indigenous to the region and which are highly toxic to man and animals.1