Enlightenment Now: The Case for Reason, Science, Humanism, and Progress

The first is to stop telling everyone they’re doomed. The fundamental fact of the nuclear age is that no atomic weapon has been used since Nagasaki. If the hands of a clock point to a few minutes to midnight for seventy-two years, something is wrong with the clock. Now, maybe the world has been blessed with a miraculous run of good luck—no one will ever know—but before resigning ourselves to that scientifically disreputable conclusion, we should at least consider the possibility that systematic features of the international system have worked against their use. Many antinuclear activists hate this way of thinking because it seems to take the heat off countries to disarm. But since the nine nuclear states won’t be scuppering their weapons tomorrow, it behooves us in the meantime to figure out what has gone right, so we can do more of whatever it is.

Foremost is a historical discovery summarized by the political scientist Robert Jervis: “The Soviet archives have yet to reveal any serious plans for unprovoked aggression against Western Europe, not to mention a first strike against the United States.”⁸⁹ That means that the intricate weaponry and strategic doctrines for nuclear deterrence during the Cold War—what one political scientist called “nuclear metaphysics”—were deterring an attack that the Soviets had no interest in launching in the first place.⁹⁰ When the Cold War ended, the fear of massive invasions and preemptive nuclear strikes faded with it, and (as we shall see) both sides felt relaxed enough to slash their weapon stockpiles without even bothering with formal negotiations.⁹¹ Contrary to a theory of technological determinism in which nuclear weapons start a war all by themselves, the risk very much depends on the state of international relations. Much of the credit for the absence of nuclear war between great powers must go to the forces behind the decline of war between great powers (chapter 11). Anything that reduces the risk of war reduces the risk of nuclear war.

The close calls, too, may not depend on a supernatural streak of good luck. Several political scientists and historians who have analyzed documents from the Cuban Missile Crisis, particularly transcripts of John F. Kennedy’s meetings with his security advisors, have argued that despite the participants’ recollections about having pulled the world back from the brink of Armageddon, “the odds that the Americans would have gone to war were next to zero.”⁹² The records show that Khrushchev and Kennedy remained in firm control of their governments, and that each sought a peaceful end to the crisis, ignoring provocations and leaving themselves several options for backing down.

The hair-raising false alarms and brushes with accidental launches also need not imply that the gods smiled on us again and again. They might instead show that the human and technological links in the chain were predisposed to prevent catastrophes, and were strengthened after each mishap.⁹³ In their report on nuclear close calls, the Union of Concerned Scientists summarizes the history with refreshing judiciousness: “The fact that such a launch has not occurred so far suggests that safety measures work well enough to make the chance of such an incident small. But it is not zero.”⁹⁴

Thinking about our predicament in this way allows us to avoid both panic and complacency. Suppose that the chance of a catastrophic nuclear war breaking out in a single year is one percent. (This is a generous estimate: the probability must be less than that of an accidental launch, because escalation from a single accident to a full-scale war is far from automatic, and in seventy-two years the number of accidental launches has been zero.)⁹⁵ That would surely be an unacceptable risk, because a little algebra shows that the probability of our going a century without such a catastrophe is less than 37 percent. But if we can reduce the annual chance of nuclear war to a tenth of a percent, the world’s odds of a catastrophe-free century increase to 90 percent; at a hundredth of a percent, the chance rises to 99 percent, and so on.