Waltzing to Armageddon?

• Author: Trachtenberg, Marc
• Position: Books

Scott D. Sagan and Kenneth N. Waltz, The Spread of Nuclear Weapons: A Debate Renewed (New York and London: W. W. Norton and Company, Second Edition 2002), 120 pp., $16.70.

THE DISTINGUISHED international relations theorist Kenneth Waltz (still) thinks that the emergence of new nuclear powers is not necessarily to be regretted. In a world of many nuclear powers, in Waltz's view, a major war would be practically impossible. He therefore believes that "more may be better"--that what has come to be called "nuclear proliferation" might actually be a good thing. Scott Sagan, a professor of political science at Stanford University and a leading authority in the field of strategic studies, disagrees; in Sagan's view, "more will be worse." In 1995, Waltz and Sagan published The Spread of Nuclear Weapons: A Debate, in which each laid out his argument and then responded to the other's argument. The discussion was spirited and often quite interesting, and the book deservedly received a good deal of attention. A revised edition, with new passages on terrorism and missile defense and a new chapter on India and Pakistan, has just been published. Its appearance provides us with a timely opport unity to confront the proliferation question yet again--a chance to get to the bottom of what is perhaps the most important international issue the world will face in the years to come.

Why does Waltz think that the spread of nuclear weapons is not necessarily to be avoided? His fundamental claim is that nuclear forces have a very powerful deterrent effect, and that nuclear states would therefore be extremely reluctant to tangle with each other. If one such state does take aggressive action--if a nuclear Iraq invaded Kuwait, for example--other powers would find it too dangerous to use military force against the aggressor state, and would only be able to take non-military measures. If the United States at the time of the Iraqi invasion of Kuwait in 1990 "had thought that Iraq might have had a few bombs, it would have had to manage the Iraq-Kuwait crisis differently, say by employing only an embargo." If, however, by some chance a limited war between two nuclear states did break out, that conflict would be very unlikely to escalate. Escalation that threatened an adversary's core interests, especially an invasion of the adversary's homeland with conventional forces, would be "too risky to conte mplate." But if a country's core interests actually were threatened, then even that situation would scarcely lead to disaster. There would be no massive escalation. Instead nuclear weapons would be used in a very limited way. A "few judiciously delivered warheads" would in such circumstances be a very effective wake-up call, and would probably "bring rapid deescalation."

A nuclear world, according to Waltz, is thus a world of safety nets beneath safety nets. In the unlikely event that serious problems between nuclear states developed at one level of conflict, the dangers would very probably be contained before matters escalated to the next level. The mere possession of a nuclear capability, Waltz says, induces "caution in any state" and "especially in weak ones." A nuclear Iraq, he now writes (Libya was the state mentioned in the corresponding passage in the 1995 text), would actually be more cautious than a non-nuclear Iraq. The possession of nuclear weapons by an adversary, moreover, would have an extremely powerful deterrent effect. In Waltz's view, "not much is required to deter." "A low probability of carrying a highly destructive attack home", he believes, "is sufficient for deterrence." A large force is not necessary for this purpose; a relatively small number of bombs would do the trick. That small force, of course, would have to be able to survive an enemy attack, bu t since bombs can be small and light, they are "easy to hide and to move" and delivering them, even after a surprise attack, would not be hard to do. "Bombs can be driven in by trucks from neighboring countries", he writes. "Ports can be torpedoed by small boats lying offshore." Even "weak and poor states", he writes, can "easily" build small, survivable nuclear forces, and when they do, they will deter even the strongest nuclear powers. With nuclear weapons, he says, "any state will be deterred by another state 's second-strike forces." Relative strength then no longer matters: "if no state can launch a disarming attack with high confidence, force comparisons are irrelevant." "A minimal deterrent", he writes, "deters as well as a maximal one."

The atomic bomb, Waltz believes, is thus the great equalizer in international politics. It is not just that a small nuclear force is as good as a big one. He now argues (in two passages that did not appear in the 1995 text) that the presence of nuclear forces also makes disparities in conventional military power meaningless. "Nuclear weapons", he says,

negate the advantages of conventional superiority because escalation in the use of conventional force risks receiving a nuclear strike. With nuclear weapons, not only is a small second-strike force equivalent to a large second-strike force but also small conventional forces are equivalent to large conventional forces because large forces cannot be used against a nuclear power.

In such a world, where neither the nuclear nor the conventional balance matters, the weak are as strong as the strong. Everyone is deterred--and deterred equally. No one will dare start a war, because the risks are so immense. There is thus practically no risk of war, or at any rate of a war in which nuclear weapons are used in a major way. In a nuclear world, a general war is a virtual "impossibility"; in such a world, "only limited wars can be fought" and "the probability of major war among states having nuclear weapons approaches zero. Nuclear weapons are thus the great bulwark of international peace; and it is because they have such a powerfully stabilizing effect that in Waltz's view the "gradual spread of nuclear weapons is more to be welcomed than feared."

SAGAN DOES NOT think a nuclear world would be nearly as stable as Waltz makes out. Indeed, looking at South Asia, he thinks that deterrence will eventually break down--that nuclear weapons will someday be used in a conflict between India and Pakistan. For him, the root problem with Waltz's argument is the assumption that states are under very strong pressure to behave rationally, and that one can therefore assume that states in fact will act rationally. To Sagan, nuclear weapons are...