Science: A Technology to Transform War

U.S., Soviets step up work on Star Wars-style beam weapons

Since scientists built the first working models two decades ago, lasers have evolved from laboratory toys into valuable tools used in microsurgery, metallurgy and communications. But while the military employs the devices to aim weapons and track targets, the development of "death rays" capable of zapping targets seemed mostly confined to Hollywood. No longer. Both the U.S. and the Soviet Union are stepping up work on so-called beam weapons. By all accounts, moreover, the Soviets lead in a technology that could revolutionize warfare.

Ordinary light, whether from the sun or a 60-watt bulb,...