The Myth of Strategic Stability
Strategic stability is one of those ideas that seem to enjoy almost unqualified support among nuclear and non-nuclear weapon states, nuclear disarmament advocates and skeptics, as well as nuclear abolitionists and nuclear hawks. And it is probably because of this universal support that the pursuit of strategic stability became the single most serious obstacle on the way toward nuclear disarmament.
Strategic stability usually refers to a state of affairs in which countries are confident that their adversaries would not be able to undermine their nuclear deterrent capability. It is generally believed that, if the nuclear deterrence potentials are secure, nuclear powers would not feel the need to build up their strategic arsenals and, most important, would not be under pressure to launch their missiles in a crisis. Understood this way, strategic stability does not seem a particularly controversial concept. Few people would advocate instability in matters that involve nuclear weapons. But the problem is that the key elements of the concept are so poorly defined that it has no useful meaning and virtually no practical value.
First of all, the numbers that are used to judge the effectiveness of deterrence have always been completely arbitrary. For example, in the early 1980s, the US intelligence agencies estimated that, in the event of a surprise Soviet attack, surviving launchers in each of the three legs of the US strategic triad could independently destroy about 70 percent of the Soviet economic value — a task that would require thousands of surviving warheads. And still the United States was concerned that this might not be enough to deter the Soviet Union. The Soviet Union, on the other hand, had a different view of what was necessary for effective deterrence: A Soviet official document from the late 1980s estimated that its retaliatory strike would destroy about 80 targets on US territory. Given that the Soviet strategic force still included more than 10,000 nuclear warheads at the time, this number does not seem particularly large. However, the authors of the estimate seemed quite confident that such a capability would provide the Soviet Union with an adequate deterrence potential.
These numbers are probably much lower today, but they are almost certainly as arbitrary as they were in the 1980s. All evidence suggests that the estimations of the number of weapons that might be required for deterrence have always been determined by the number of weapons available — rather than the other way around. So, once nuclear states start cutting down their nuclear arsenals, they have no problem adjusting their views of efficient deterrence accordingly. In August, for example, a former commander of the US Strategic Command stated on record that “the retaliatory capability of 300 nuclear weapons on anybody’s territory is catastrophic.” But there is no reason to believe that the retaliatory capability of, say, 30 nuclear weapons — or even three — is anything but catastrophic. Indeed, the experience of the Cuban Missile Crisis or concerns about the emerging nuclear capabilities of countries like North Korea and Iran tells us that just a small probability of having a single nuclear weapon delivered to someone’s territory is a very strong deterrent.