President Carter has signed a directive that modifies US strategy in nuclear war to emphasize destruction of Soviet military targets and command centers rather than cities, defense officials said Wednesday.
The shift in emphasis away from massive retaliation toward what Defense Secretary Harold Brown calls "countervailing strategy" began under Defense Secretary James Schlesinger in 1974. The theory is that retaliating against the Soviet Union by striking its major cities and industrial centers is too drastic an option for the nuclear age of today.
The shift in doctrine has also been prompted by the Soviet approach to war in the nuclear age. The soviets for some years have stressed the need to destroy US strategic weapons and communication systems and have been developing the weapons to do so.
Over the last three years, the administration has been moving in this direction by developing more accurate nuclear weapons, such as the MK- 12A warhead being deployed on Minuteman III missiles, and with the Navy's new Trident I missile.