The elaborate nuclear strategies promoted by RAND and embraced by McNamara now seemed largely irrelevant. After the Cuban Missile Crisis, a “no cities” policy lost its appeal. Newspapers had criticized it, NATO allies had repudiated it, and the dispersal of SAC bombers to commercial airports had blurred the distinction between civilian and military targets. And as the Soviet Union built more long-range missiles, a counterforce strategy would require the United States to deploy more missiles to destroy them. The arms race would become never ending. The hope of eliminating the Soviet threat with a first strike and defending America from attack now seemed illusory. Thousands of new missiles, the construction of more bomb shelters, or even an antiballistic missile system couldn’t change what appeared to be an unavoidable fact for both superpowers: launching any nuclear attack would be suicidal.
Within weeks of President Kennedy’s assassination, McNamara formally endorsed a strategy of “Assured Destruction.” The idealism and optimism that had accompanied Kennedy’s inauguration were long gone. The new strategy was grounded in a sense of futility. It planned to deter a Soviet attack by threatening to wipe out at least “30 % of their population, 50 % of their industrial capacity, and 150 of their cities.” McNamara’s staff had calculated that the equivalent of 400 megatons, detonated above the Soviet Union, would be enough for the task. Anything more would be overkill. Informed by a reporter that the Soviets were hardening their silos to protect the missiles from an American attack, McNamara said, “Thank God.” The move would improve “crisis stability.” Once the Soviets felt confident that they could retaliate after being attacked, they’d feel much less pressure to strike first. Leaving the cities of the United States and the Soviet Union vulnerable to annihilation, McNamara now thought, would keep them safe. The strategy was soon known as MAD: “mutually assured destruction.”
The strategic thinking at the White House and the Department of Defense, however, didn’t correspond to the targeting policies at SAC headquarters in Omaha. The gulf between theory and practice remained vast. Although the SIOP had been revised during the Kennedy administration, General Power had blocked significant changes in weapon allocation. The new SIOP divided the “optimum mix” into three separate target groups: Soviet nuclear forces, conventional military forces, and urban-industrial areas. The president could decide to attack only the first group, the first two groups, or all three. Moscow, China, and cities in the Eastern bloc could selectively be spared from destruction. The SIOP could be launched as a first strike or as retaliation. But all the attack options still required that the Soviet Union be hit by thousands of nuclear weapons, far more than were necessary for “assured destruction.” The three target categories of the SIOP — Alpha, Bravo, Charlie — were the same as those in the attack plan proposed by SAC in 1950. And the new SIOP was almost as destructive, inflexible, and mechanistic as the previous one. A war plan that seemed too horrible to contemplate when Kennedy and McNamara first learned of its existence had become institutionalized.
By the time Robert McNamara retired from the Pentagon in February 1968, the command-and-control system of the United States had been improved. The new Missile Defense Alarm System — satellites with infrared sensors that could detect heat from the launch of missiles — promised to give as much as half an hour of warning, if the Soviets attacked. SAC’s Looking Glass command post, airborne twenty-four hours a day, increased the likelihood that a Go code could be sent after the United States was hit. New computer and communications systems were being added to the World Wide Military Command and Control System. But many of the underlying problems hadn’t been solved.
