In an article entitled "Peace, Stability, and Nuclear Weapons," Kenneth N. Waltz presents the theory that nuclear proliferation does not increase the risk of war.
He lists seven possible reasons why countries want nuclear weapons:

1)Great powers always counter the weapons of other great powers, by imitating those who have introduced new weapons. Evidence of this is the fact that the Soviet Union developed atomic and hydrogen bombs.
2) A state may fear that its great power ally will not retaliate if another nation with nuclear capability attacks.
3) A country will especially want nuclear weapons if some of its adversaries have them. Sequence of countries becoming nuclear powers: China, then India, and naturally, Pakistan.
4) Fear of its adversaries' present or future conventional strength.
5) Nuclear weapons may be a cheaper and safer alternative to an economically ruinous and militarily dangerous conventional arms race.
6) For offensive purposes, although this is unlikely for reasons below.
7) By building nuclear weapons, a country may hope to enhance its international standing.

The following are reasons to fear the further spread of nuclear weapons: - Offensive use by new nuclear states
- increased chances of accidental use
- with limited knowledge and resources, new nuclear states may find it difficult to deploy invulnerable, deterrent forces
- U.S. military intervention in affairs of lesser states will be impeded
- terrorists may more easily get hold of nuclear materials

Waltz claims that what states do conveys more than what they say. He uses Idi Amin and Muammar el-Qaddafi as examples to say that despite wild rhetoric aimed at foreigners, both became cautious and modest when punitive actions against them threatened their continued ability to rule. Some may question what could happen if a hostile Syria obtained nuclear arms. What would stop Syria from destroying Israel? But Waltz asks rhetorically whether any rogue nation would do so at the risk of Israeli bombs falling on some of their cities. Rulers want a country that they can continue to rule. For this reason, we cannot expect countries to risk more in the presence of nuclear weapons than they did in their absence.

One main point of Waltz's argument is that nuclear weapons make states cautious. Rogue states, as the Soviet Union and China were once thought to be, have followed the usual pattern. The weaker and more endangered the state is, the less likely it is to engage in reckless behavior.

Next, Waltz points to half a century of nuclear peace to discuss the control of nuclear weapons. He argues that all nuclear countries live through a time when their forces are crudely designed, and so far, all countries have been able to control them. Thus there is no reason to expect new nuclear states to experience greater difficulties than the ones with which the old nuclear states were able to cope. "We do not have to wonder whether they will take good care of their weapons. They have every incentive to do so. They will not want to risk retaliation because one or more of their warheads accidentally strikes another country."

Waltz does mention the possibility that a nuclear state may experience uncertainty of succession and regime instability, and one side in a civil war firing a nuclear warhead at the opponent's stronghold. He points out, however, that this would produce a national tragedy, not an international one.

In addition, it does not take much to deter. Requirements are low. To have second-strike forces, states do not need large numbers of weapons.

Waltz dismisses the likelihood of nuclear terror as low, and even if it were not, terrorists would be able to steal nuclear weapons or find illegal means to purchase them regardless of whether or not a few more states go nuclear.

Finally, Waltz states that nuclear weapons do not make lesser states into great powers. What nuclear weapons do is enable the weak to counter some of the measures that the strong may wish to take against them.

Waltz concludes with the idea that peace has become the privilege of states having nuclear weapons, while wars are fought by those who lack them. The behavior of a nation is strongly conditioned by the world outside, and weak authoritarian rulers often avoid war for fear of upsetting the balance of internal and external forces. Waltz suggests that the biggest dangers come from the biggest powers and the smallest from the smallest. We should be more fearful of old nuclear countries and less fearful of recent and prospective ones.

Efforts should be directed towards ensuring the security of large arsenals rather than keeping weak states from obtaining the small number of warheads they may believe they need for security.

Kenneth N. Waltz is Adjunct Professor at Columbia University
Adapted from "Peace, Stability and Nuclear Weapons," Art, Robert J. and Kenneth N. Waltz, The Use of Force, New York: Rowman & Littlefield Publishers, 1999.