Defense strategists today assume that a single Soviet warhead detonated 200 miles above Nebraska would knock out unprotected communications equipment all across the United States. The reason is electromagnetic pulse (EMP), a by-product of high-altitude nuclear explosions that blankets huge tracts of the earth with peak fields of 50,000 volts per meter.
The first installment of this three-part series described how EMP was discovered and why its potentially chaos-producing effects were overlooked for more than a decade. The second part examines the ongoing debate in the Pentagon over how to cope with the EMP threat. The third part will discuss questions EMP raises about waging a limited nuclear war.