Secretary of Defense Robert McNamara had his hands full trying to set criteria for nuclear requirements at a time when the training and ethos of the Strategic Air Command called for taking the initiative and winning decisively. McNamara’s braininess, his coterie of civilian “whiz kids,” and their attachment to cost-effectiveness methods alien to the Pentagon brass, generated great friction. None were more affronted that General Curtis LeMay, the head of SAC, who thought McNamara “was turning his country’s back on the capacity for victory though air power in nuclear war.”
This quote comes from McGeorge Bundy’s masterful Danger and Survival, Choices about the Bomb in the First Fifty Years (1988). McNamara briefly considered a “damage limitation” nuclear posture, which meant avoiding cities and targeting opposing forces that could do great harm. But this targeting doctrine invited open-ended targeting requirements: the more damage limitation capability the U.S. fielded, the more targets the Soviet Union could be expected to proliferate. Besides, many key targets, including command and control nodes, were presumably located in or near cities.
So McNamara embraced the notion of assured destruction, which was not to be confused with minimal, credible deterrence. In support of his assured destruction strategy, McNamara picked the nice, round number of 1,000 ICBMs. Again, here’s Bundy:
“When he chose to have 1,000 Minuteman missiles, he was choosing a number that Congress would find acceptably large, not a number that he himself could demonstrate as strategically necessary. There were critics who argued then and later that a smaller number would have been enough, but the politically important alternatives before McNamara at that time were those desired in the Air Force – anywhere from 2,400 missiles to 10,000.”
McNamara initially quantified assured destruction as the ability to absorb a Soviet first strike and then kill, by immediate effects, 25 to 30 percent of the Soviet population as well as two-thirds of Soviet industry. Later, he adjusted these percentages downward a bit, to 20-25 percent of the Soviet population and 50 percent of Soviet industrial capacity.
Assured destruction was all well and good, until the Soviet Union embraced big numbers of its own, whether because of paranoia, domestic, bureaucratic and interest group drivers – or as U.S. Hawks surmised, because the Kremlin planned to fight and win a nuclear war. The superpowers became enmeshed in a nuclear competition fueled by the twin impulses of seeking advantage and fearing disadvantage. How else could one explain the trajectories on which the United States and the Soviet Union would produce over 100,000 nuclear weapons during the Cold War? This competition invited catastrophe. A blunting diplomatic instrument was needed, and a coterie of academics, mostly from Cambridge, called this construct arms control.