Learning to love the bomb: is nuclear proliferation inherently dangerous? (Culture & Reviews).

The Spread of Nuclear Weapons: A Debate Renewed, by Scott D. Sagan and Kenneth N. Waltz, New York: W.W. Norton & Co., 220 pages, $18.50

WITH THE UNITED States in a wartime mode with respect to both Al Qaeda and Saddam Hussein, Americans may have forgotten the scale of the danger that confronted them just a few years ago. The Soviet Union then fielded a huge army that had bested the Wehrmacht and was fully capable of gobbling up large chunks of Western Europe. It supported "liberation movements" around the world with arms and money. It operated a spy network that stole some of our most sensitive and tightly guarded security secrets. And, not least, it maintained an arsenal of thousands of nuclear weapons. During the superpower standoff, every American was half an hour from nuclear annihilation.

Anyone looking ahead from when this standoff began, would have glumly expected that sooner or later the two sides would come to savage blows. But the most striking fact about the Cold War was its peacefulness. Not only did all those nuclear weapons go unused, but American and Soviet soldiers never met on the field of battle. Historian John Lewis Gaddis argued that the period was misnamed: Instead of the Cold War, he said, it may well be remembered by history as the Long Peace. Writing in 1987, he noted that it compared favorably "with some of the longest periods of great power stability in all of modern history."

In a century marked by the greatest and most deadly wars ever seen, this era of tense truce came as a surprise, and might be seen as a miracle. But nothing supernatural was involved. Human nature didn't suddenly change. Nations didn't cease to regard each other with suspicion and distrust. But at least one important thing made the postwar world different: the invention of atomic weapons. As the military theorist Bernard Brodie wrote in the aftermath of Hiroshima and Nagasaki, "Thus far the chief purpose of our military establishment has been to win wars. From now its chief purpose must be to avert them."

Each side had a powerful interest in avoiding any conflict that could escalate out of control. Although no one expected it at the outset, a durable though uneasy form of peace took hold. Yet the same nations whose power and security have been underwritten by nuclear weapons have labored mightily to prevent anyone else from getting them.

When North Korea built a nuclear reactor capable of providing fuel for bombs, the United States and South Korea bribed Pyongyang into giving it up--though it turns out that the regime apparently acquired a nuclear arsenal anyway. When India and Pakistan carried out nuclear tests, Washington imposed sanctions on both. Today President Bush's policies toward Iraq spring from the fear of a nuclear-armed Saddam Hussein. It may not be long before the administration turns its attention to another longtime enemy with nuclear ambitions: Iran.

In a world where nuclear weapons are the ultimate protection, many countries feel an urgent need to acquire them, and some are bound to succeed. That prospect raises a question rarely considered: Is it possible that the world would be better off with more nuclear states?

In The Spread of Nuclear Weapons:

A Debate Renewed, Columbia University political scientist Kenneth Waltz makes an exhaustive case that "the gradual spread of nuclear weapons is more to be welcomed than feared." Stanford political scientist Scott Sagan replies that nuclear weapons do not prevent human beings from making mistakes but "only make their inevitable mistakes more deadly." This book, a revised and expanded version of their 1995 volume on the same subject, addresses crucial issues in a clear and provocative way that should engage newcomers and stimulate rethinking by those familiar with the subject.

Waltz argues convincingly that the incentives inherent in a nuclear world work vigorously to keep even fierce disputes from turning into armed conflicts and to keep armed conflicts from escalating. "In a conventional world, one is uncertain about winning or losing," he writes. "In a nuclear world, one is uncertain about surviving or being annihilated....When these are the pertinent questions, we stop thinking about running risks and start worrying about how to avoid them."

That tendency is evident not only in the U.S.-Soviet experience but in the standoff between India and Pakistan. During the 1999 fighting between the two nations, Waltz concludes, "the presence of nuclear weapons prevented escalation from major skirmish to full-scale war." The same logic held in 2002 when the two sides made a public display of preparing for war over Kashmir. Each government tried to make the other believe it was willing to weather a nuclear war if need be, but each was also careful to avoid giving the other a reason to start one, In the end, the war was averted, or at least postponed.

Waltz's logic serves to rebut the warnings heard during the last year about the threat that we would face if Saddam Hussein acquired nuclear weapons. We're told that he would use them because he has a history of reckless aggression. But Stalin and Mao were also regarded as determined expansionists, and we managed to deter them from using their nukes.

One scenario pictures Hussein, armed with nukes, invading Kuwait or Saudi Arabia and then forestalling American intervention by threatening to incinerate New York. But this is not a new kind of fear. During the 1960s, writes Waltz, "Some American commentators worried that the Soviet Union might suddenly seize Hamburg, which jutted into East Germany, and then in effect ask, 'Is NATO's fighting to regain Hamburg worth risking a nuclear conflagration?'"

For that matter, China could have tried to use its atomic arsenal to cover an occupation of Hong Kong. But the risk of bringing on nuclear retaliation was too much to bear. To say that a country like Iraq or North Korea could use nuclear weapons for offensive purposes is to say, as Waltz puts it in a different context, "that although the strong can deter the strong as the United States and the Soviet Union did...the strong cannot deter the weak."

Sagan doesn't contest the fundamental logic of nuclear deterrence. His fears about the consequences of proliferation are mostly practical ones stemming from some troubling episodes during the Cold War and from the basic fallibility of human organizations. Despite the possibility of nuclear retaliation, American military planners urged Presidents Truman and Eisenhower to launch preventive nuclear strikes against the Soviet Union. Sagan argues that military officers may see nuclear war as inevitable, making them susceptible to the idea that it's best to strike first.

What seems like the obvious logic of deterrence today was not always apparent. The key to deterrence is a second-strike capacity-the ability to absorb an attack on one's nuclear arsenal and still mount a nuclear response. If a country does not have that ability, its adversary may be moved to launch a pre-emptive strike. When both sides have a second-strike capacity, neither can hope to gain from going first, which fosters caution and stability.

Sagan notes that the most invulnerable part of the American nuclear force is on submarines--a system "developed against the wishes of the U.S. Navy leadership," which preferred to spend money on traditional weapons. China, which became a nuclear power in 1964, didn't bother to make its force invulnerable until the 1980s. But Third World states may lack the resources to assure the survivability of their stockpiles, or they may simply neglect that need.

In a crisis, Sagan fears, misinformation may spawn catastrophe, and less developed countries like India and Pakistan may lack the warning systems needed to know what they need to know. A conventional bomb dropped on a target might be perceived as a nuclear strike. The people in charge of the bombs also maybe unreliable. The U.S. military administers psychological tests to nuclear weapons personnel, says Sagan, and each year it decertifies up to 5 percent of them. Pakistan has no such program. In a country teeming with Islamic extremists, that's ample cause for discomfort.

In this debate, Waltz is the micro-economist, arguing that the correct incentives will produce the most efficient outcomes. Sagan is the organizational theorist, conceding that this may be true in the long run while noting that in the short run there may be lots of mistakes, including some major ones. In the economic realm, such errors are tolerable. In the nuclear realm, the costs are vastly greater.

Nuclear weapons are fundamentally status quo weapons, inducing caution and promoting stability. In the last half-century, they undoubtedly served as a strong check on the superpowers, and under the right conditions they could diminish the incidence of conventional war.

It's entirely possible--maybe even probable--that the world will grow more peaceful as more states go nuclear, and that the Bomb will never again be used. But the Gold War, though reassuring, provides an awfully small sample by which to judge what will happen in a world beset by steady proliferation.

To judge the effects of nuclear weapons, we need a lot more information drawn from real-world experience. For better or worse, we're going to get it.

Steve Chapman ([e-mail]) is a columnist and editorial writer for the Chicago Tribune.