ASHINGTON As the United States moves closer to war with Iraq, some have suggested relying instead on deterrence to deal with the threat Saddam Hussein poses. Those who favor deterrence acknowledge that the containment regime that constrained Iraq during the 1990's has frayed beyond repair, but argue that Mr. Hussein can still be kept in check by American threats to respond to any new Iraqi aggression with force — including nuclear bombardment, if necessary.
Certainly war should be a last resort, and deterrence is a seemingly reasonable alternative; after all, it worked with the Soviet Union for 45 years. Unfortunately, however, those who seek to apply it to Iraq base their views on a dangerous misreading of Mr. Hussein, and so fail to recognize how risky such a course is likely to be.
Proponents of deterrence argue that Mr. Hussein will not engage in new aggression, even after he has acquired nuclear weapons, because he is not deliberately suicidal and so would not risk an American nuclear response.
But what they overlook is that Mr. Hussein is often unintentionally suicidal — that is, he miscalculates his odds of success and frequently ignores the likelihood of catastrophic failure. Mr. Hussein is a risk-taker who plays dangerous games without realizing how dangerous they truly are. He is deeply ignorant of the outside world and surrounded by sycophants who tell him what he wants to hear.
When Yevgeny M. Primakov, a Soviet envoy, went to Baghdad in 1991 to try to warn Mr. Hussein to withdraw, he was amazed to find out how cut off from reality Mr. Hussein was. "I realized that it was possible Saddam did not have complete information," he later wrote. "He gave priority to positive reports . . . and as for bad news, the bearer could pay a high price." These factors make Mr. Hussein difficult to deter, because his calculations are based on ideas that do not necessarily correspond to reality and are often impervious to outside influences.
In 1974, for example, he attacked the Kurds even though Iran had been arming and supporting them (with American and Israeli support). He believed, for reasons unknown, that Iran would do nothing to help its proxies. The shah responded decisively, sending troops into Iraqi Kurdistan, mobilizing his army and provoking clashes along the border. To stave off an Iranian invasion that he feared would end his regime, Mr. Hussein was forced to sign the humiliating Algiers accord, which gave Iran everything it wanted from Iraq, including contested territory.
This pattern has been repeated many times since, and it is fair to say that Mr. Hussein's continued survival is far more attributable to luck than it is to any prudence on his part. Thus in 1980 he attacked Iran under the misguided assumption that the new Islamic Republic was so unpopular that it would collapse after one good shove. In so doing, he embroiled Iraq in a war that nearly destroyed his own regime.
In 1991, rather than withdrawing from Kuwait and heading off a war, he convinced himself that the American-led coalition would not attack and that even if it did, his army would emerge victorious. By confidently pursuing this path he again nearly destroyed himself and his regime.
The best evidence that Mr. Hussein can be deterred comes from the Persian Gulf war, when he refrained from using weapons of mass destruction because of American and Israeli threats of nuclear retaliation. But a closer look at the evidence provides more ominous lessons.
When Secretary of State James Baker met with Tariq Aziz in Geneva on the eve of the war, the letter he presented from President Bush to Mr. Hussein threatened the "severest consequences" if Iraq took any of three actions: use of weapons of mass destruction, destruction of the Kuwaiti oil fields or terrorist action against the United States.
The first point to make is that this did not stop Mr. Hussein from destroying the oil fields or dispatching hit squads to the United States, so the notion that he is easily deterred is dubious. Mr. Hussein did not use chemical munitions against coalition ground forces because he initially believed that he did not need them to prevail. Nevertheless, he did keep stockpiles farther back from the front, suggesting he planned to use them if the battle did not go as he expected. Whether he would have used these weapons is an open question, because the coalition ground advance was so rapid that Iraq's forces never had a chance to deploy them.
A better case can be made that Mr. Hussein was deterred from launching Scud missiles tipped with chemical or biological agents at Israel for fear that the Israelis would retaliate with nuclear weapons, but even here the evidence is hardly perfect. After the war, United Nations weapons inspectors reported that the Iraqi engineers knew that their warheads were awful and probably would have done little damage. For this reason, Mr. Hussein might have considered the conventionally armed Scuds to be the most potent arrows in his quiver.
After the gulf war, moreover, United Nations inspectors and Iraqi defectors revealed a set of secret plans and orders, issued by Mr. Hussein, that are disturbing at best. First, he had set up a special Scud unit with both chemical and biological warheads that was ordered to launch its missiles against Israel in the event of a nuclear attack or a coalition march on Baghdad. Since no one outside Iraq knew at the time about this unit and its orders, it was clearly intended not as a deterrent but simply as a force for revenge.
Second, in August 1990 — after he realized that the United States might challenge the invasion of Kuwait — Mr. Hussein ordered a crash program to build one nuclear weapon, which came close to succeeding. (It failed only because the Iraqis could not enrich enough uranium in time.) His former chief bombmaker has said that Mr. Hussein intended to launch the bomb as a revenge weapon at Tel Aviv if his regime started to collapse. His former chief of intelligence has said that he believes that Mr. Hussein wanted to build a nuclear weapon in order to deter the United States from launching Desert Storm.
Third, Iraqi defectors and other sources report that Mr. Hussein told aides after the war that his greatest mistake was to invade Kuwait before he had a nuclear weapon, because then the United States would never have dared to oppose him.
What all this suggests is that if Saddam Hussein is able to acquire nuclear weapons, he will see them as tools to achieve his goals — to dominate the Arab world, destroy Israel and punish America. He might not launch such weapons immediately in pursuit of these aims, but that is cold comfort. There is every reason to believe that he would brandish them to deter the United States from interfering in his efforts to conquer or blackmail neighboring countries.
With 1990's-style containment fading quickly and unlikely to be revived, both of the remaining Iraq policy options — invasion and deterrence — carry serious costs and risks. But a well-planned invasion, one that mustered overwhelming force and the support of key allies, could keep those risks to a minimum.
On the other hand, staking our hopes on a policy of deterrence would cost little now (except a loss of face), but it would run the much greater risk of postponing the day of reckoning to a time of Iraq's choosing. Given Mr. Hussein's history of catastrophic miscalculations and his faith that nuclear weapons can deter not him but us, there is every reason to believe that the question is not one of war or no war, but rather war now or war later — a war without nuclear weapons or a war with them.
Kenneth M. Pollack, a former C.I.A. analyst of the Iraqi military, is director of research at the Saban Center for Middle East Policy. He is author of "The Threatening Storm: The Case for Invading Iraq."