Since Iraq's Aug. 2 invasion of Kuwait, the U.S. intelligence community has intensified its efforts to answer a question of fundamental interest to U.S. forces deployed in the Persian Gulf: Could Iraqi scientists produce one or more crude nuclear weapons in the near future? So far, according to U.S. officials and nuclear proliferation analysts outside the government, the answer appears to be:

It's possible, but not probable.

"There is a certain nuclear hypothesis that can be drawn about Iraq's program," said one administration official who has examined the most recent CIA assessment of the program. "And while the hypothesis is possible -- in other words that they could design a bomb -- there are still questions about whether it would work and whether it would be sufficiently powerful to constitute a military capability."

Added Leonard S. Spector, a nuclear nonproliferation expert at the Carnegie Endowment for International Peace, "They would have only one shot so you have to ask whether they would be in a posture to make their nuclear threat credible."

For Iraq, the key to any attempt at fashioning a nuclear explosive is mastery of the sophisticated weapons design and fabrication technology required to use the small amount of "bomb grade" uranium Iraq possesses to make one or more weapons, according to U.S. physicists, nuclear proliferation experts and Bush administration officials.

The consensus remains, according to U.S. officials, that Iraq's nuclear scientists lack such sophistication and that the complex production methods needed to fashion usable nuclear weapons are still beyond Iraqi capabilities.

One U.S. official who has reviewed CIA studies of the Iraqi program said even U.S. nuclear weapons designers would find it very difficult to fabricate a credible weapon from the small amount of highly enriched uranium that was supplied to Iraq by France as fuel for a French-built research reactor. The reactor program -- along with plans for French shipment of an additional quantity of highly enriched uranium fuel -- ended when the reactor was destroyed by Israel in a 1981 air raid.

But some U.S. officials are hedging their bets.

"Within a year, they could come up with a crude bomb," said a Defense Department official, who said he drew a more alarming conclusion from the CIA's recent assessment of Iraqi nuclear research. "It is a real threat," he said of the Iraqi effort, "certainly within the realm of the possible."

Concern also has increased as the U.S. military buildup has mounted and Iraqi President Saddam Hussein has threatened Washington with daunting casualties if U.S. forces attack Iraq and its occupation army in Kuwait.

"This man has a history of looking for the magic weapon in the Iran-Iraq war, the silver bullet that can solve all his problems," said one U.S. intelligence official, referring to Iraq's chemical weapons and ballistic missile programs that were crucial factors in Iraq's victory in its eight-year war with Iran.

"We certainly expect him to attempt to accelerate any program," the official said, "such as his nuclear program" that would give him that "silver bullet" capability against U.S. forces.

According to officials, there is no hard evidence that Iraq has actually accelerated its nuclear research since the Kuwait invasion. But the intelligence community appears to take it as a given that Saddam is forging ahead.

One Arab diplomatic source, whose government pursues an active intelligence network in the Middle East in conjunction with the United States, said, "We think that Saddam Hussein has made a very aggressive attempt since the invasion, since the American troops were deployed there" to push his nuclear scientists to produce the first Iraqi atomic bomb. "Our information is that his instructions are that 'I want something within 12 months,' " the source said, adding, "His people are telling him it's close to impossible, but he is pushing for it."

Iraq's attempts to import Western technology that could further its nuclear weapons research program have attracted worldwide attention and condemnation in the past year. Iraqi officials insist that their nuclear research efforts are peaceful, geared to medical uses and electric power generation.

After the Soviets first sold Iraq a small research reactor in the 1960s, Iraq became a signatory to the Nuclear Non-Proliferation Treaty and agreed to open its facilities to inspection by the International Atomic Energy Agency (IAEA) in Vienna.

Iraqi officials, who bristle at charges that they are seeking a nuclear weapon, often point out that while they have opened their facilities to inspection, Israel has not.

Israel's concerns about Iraqi nuclear research led to the June 7, 1981, bombing raid on Iraq's nuclear complex south of Baghdad, where Israeli warplanes irreparably damaged the 40-megawatt Osirak research reactor before it went operational and before a full load of fuel had been delivered to the site. The reactor was purchased from France.

Thirty-nine fuel assemblies, containing 25 pounds of highly enriched uranium, survived the bombing and have been inspected at least twice a year by the international agency since the raid.

Fears of an Iraqi bomb usually center on this supply of uranium. Under the scenario, the enriched uranium would be "diverted" to an illicit bomb project. But the world would be alerted because Iraq would be forced to cancel IAEA inspections.

The next inspection of Iraq's nuclear fuel is scheduled for later this month, according to U.S. officials, some of whom have expressed concern that the Iraqi regime may cancel it.

"If he {Saddam} refuses the inspection, that alerts the world," said Richard Wilson, former chairman of Harvard University's physics department.

A second, less urgent concern about Iraq's nuclear program is Iraq's acquisition of the first gas centrifuge machines that can process tiny amounts of highly enriched uranium from uranium ore. Iraq has about 200 tons of uranium ore, or yellow cake, stockpiled for unspecified use.

But Iraq would need a thousand or more centrifuge machines working full time to yield enough "weapons grade" uranium to begin producing bombs. U.S. intelligence officials said such an industrial effort has not begun and would likely take at least five years or more, assuming Iraq could locate the centrifuge technology to go forward.