A nuclear attack on the U.S. might consist of hundreds of missiles or a few. One military base, or scores of cities, might be targeted. But the results are chillingly predictable. The following hypothetical scenario is based on a study by the congressional Office of Technology Assessment.
Say it is late April, a cloudless Thursday evening in Detroit. Assume further that there is no advance warning. Shortly after 8:30, the lone warhead of a Soviet SS-13 missile comes swooping down. Six thousand feet, directly above the intersection of Interstate Highways 94 and 75, the 1-megaton bomb—only a fiftieth as large as the...