Some thirty years ago , the Rand corporation , America's formost cold war think tank, faced a strange straegic problem. How could the US authrieties succesfully communicate after a nuclear war? Postnuclear America would need a comand-and-control network, linked from city to city , state to state, base to base . But no matter how throughly that network was armored or protected , its switches and wiring would always be vulnerable to the impact of atomic bombs. A nuclear attack would reduce any conceivable network to tatters. And how would the ....