PERSPECTIVE ON WAR : Iraqi Nuclear Capacity: Small, but Big Enough : The West is about to learn, possibly in this desert showdown, the futility of its strategies to restrict proliferation.

If Iraq and the United States go to war in the desert, the odds are improving that two nuclear-armed nations will face each other across open sights for the first time.

Without question, Saddam Hussein’s atomic scientists are capable of turning out the combinations of high explosives and electronics necessary to initiate a nuclear explosion. The physics of nuclear weapons is well known, and fabrication of the actual bombs is not difficult for a country, such as Iraq, that makes its own conventional munitions and long-range rockets. And Iraq has 27 pounds of uranium in its possession, provided by the French as part of the Osirak reactor project, which is ample for the construction of at least one nuclear weapon.

Iraqi scientists are unlikely to produce devices that are either crude, heavy or low in yield. While probably not light enough to fit on the tip of one of Iraq’s locally modified Scud missiles, an Iraqi atomic bomb would surely be light enough to be delivered by fighter plane, either MiG or Mirage, and more powerful than the weapon that flattened Nagasaki.

Nuclear weapon designs which seem to be far more advanced than those used against Japan have surfaced in the press in the United States and, more important, in Sweden. Scientists working on Sweden’s now-discontinued weapons project knew that they could have produced lightweight and efficient bombs. The Swedes were also confident that their devices would have worked as planned, even without testing. If Iraq implements Swedish-type designs using the same care and attention to detail it has shown in its adaptations of Soviet Scud missiles and the construction of its own longer-range rockets, Saddam Hussein has enough nuclear fuel for at least two atomic weapons. If he can obtain relatively small amounts of plutonium to enrich the mixture, it is not impossible that his scientists could produce as many as three nuclear charges.

The smallest amount of fuel ever used to produce a nuclear explosion is far less than the “trigger quantities” that supposedly mark the minimum needs for a weapon. These international limits are politically negotiated ceilings, not scientifically established thresholds.

In the months preceding the Aug. 2 invasion of Kuwait, Iraq entered the international marketplace to acquire the capacitors and krytron tubes used in some modern nuclear weapons. The system of controls on the sale of such nuclear-capable components apparently worked in part and limited the number that Iraq could obtain. While neither device is necessary (neither was used by the weapon makers of Los Alamos in 1945), Iraq’s purchases give an important clue to the progress of its nuclear weapons program and the intentions of Saddam Hussein.

If Iraq’s nuclear weapons project were years away from producing its first bomb, there would have been little need to seek out hardware that is useful only in the “endgame,” when implosion systems are mated to fissile material. Iraq’s plunge into the atomic market last summer was probably the first tick of a countdown clock that needs less than a year to reach zero.

Iraq’s scientists will need to do some experimenting to produce bombs in which they can have confidence, but those experiments need not involve nuclear explosions or more than a thimbleful of uranium. The tests required to establish confidence in the nuclear initiator and the implosion explosives will produce no perceptible nuclear yield and can be carried out in any munitions factory, mine or quarry. They are unlikely to have a distinctive signature observable by U.S. or Soviet spy satellites. Adequate test instrumentation can be improvised from simple equipment not much more sophisticated than a cork and some pins.

The United States, and the other allied nations facing Iraq, might not know the status of the Iraqi weapons program until Saddam Hussein himself chose to make an announcement, perhaps an explosive one.

The West has pretended to limit nuclear proliferation by controlling access to the kind of equipment its laboratories would use today to design or build nuclear arms. It is far more important to eliminate the availability of the essential fissile isotopes, pure plutonium-239 and highly enriched uranium- 235. Nuclear weapons can be made without krytrons, but not without fissile material, and Saddam Hussein has highly enriched uranium in his pantry.

So long as Iraq claims that it is not making a bomb, its nuclear facilities are subject to only intermittent inspection by officers of the International Atomic Energy Agency. An audit of Iraq’s uranium, which is under international seal, was conducted recently; another is not scheduled until long after the Jan. 15, 1991, deadline. Only a few weeks need pass from the time the seal is broken until the uranium is incorporated into nuclear weapons.

The United States and its allies may be about to learn the value of uranium in the hands of a dictator, and the futility of Western attempts to thwart nuclear proliferaters by restricting their access to peripheral technologies.