The Iraqi-Iranian war is bound to sputter out "in a matter of days" if for no other reason than Iran has been unable to get its American-supplied arsenal to the battlefield, Pentagon officials said yesterday.

As billions of dollars in weaponry the late Shah Mohammed Reza Pahlavi bought from the United States go unused, these officials added, Iran is running short of something it did not have to buy from anybody else: airplane fuel.

With Iraq consolidating its gains on the ground rather than advancing significantly deeper into Iran, together with Iran's disarray, the Pentagon sees the war ending "in a matter of days, not weeks," to quote one top official.

Baghdad is assuring other capitals, said government officials familiar with the cable traffic, that its military has no intention of advancing deep into Iran but instead will hold onto the disputed territory while diplomats negotiate a settlement to the war.

However, U.S. State Department officials were not optimistic yesterday about the prospects of such a negotiated settlement, at least not a quick one. Officials say both countries seem to be seeking the overthrow of the ruling powers of the other, and those objectives are not negotiable.

U.S. military officials blame the Ayatollah Ruhollah Khomeini government's purge of many top Iranian officers for the poor showing of the Iranian army and air force.

One example, they said, is the fact the the Iranian division that was called the 77th during the shah's reign, left its position on the Soviet border last week but still has not arrived at the front in force.

In describing the disarray, the officials also cite the inability of Iran to use its troop-carrying helicopters to drop behind Iraqi positions or to employ its helicopter gunships. Iran bought from the United States six RH53D troop helicopters and 202 AH1J Sea Cobra gunships when the Shah was in power.

The sea Cobra gunships, which the Iranian air force has been flying since 1974, are considered ideal by Pentagon officials for attacking Iraqi troops spread out in the desert.

While poor maintenance and lack of spare parts may help explain the absence of the helicopters, Pentagon officials said the same cannot be said of antitank missiles.

The Pentagon estimates that Iran had an arsenal of about 14,000 antitank missiles when Iraqi armor invaded. But the Iraqi advances indicate that relatively few of the easily maintained and easily fired missiles have been used.

Most of the antitank missiles were TOWs, which South Vietnamese troops used to stop North Vietnameses armor in their unsuccessful Easter offensive of 1972.

Iran also was rich in artillery and air defense weaponry, but apparently could not use that with any degree of sophistication, either.

The Pentagon said that Iran bought more than 1,000 artillery pieces from the United States, including 900 highly mobil 105 mm and 155 mm howitzers. A cohesive Iranian command structure could have moved those howitzers into actionon the front in a hurry, specialists said.

Iran bought about 1,800 Improve Hawk antiaircraft missiles from the United States. But they require a coordinated radar warning net to work effectively, something Iran does not have.

Also, Pentagon officials said, the air war between Iraq and Iran was nothing like the ones in the Vietnamese and Arab-Israeli wars. In those conflicts, pilots were guided to their jets by sophisticated command centers on the ground and were up against a two-layer defense of low-altitude and high-altitude antiaircraft missiles.

In contrast, one or two Iraqi and Iranian planes at a time wander around the sky on most days, dropping bombs helter-skelter.

"The pictures of an oil storage tank burning up made it look like the air war was bigger than it was," said one Pentagon officials.

Although the United States received little intelligence from people in Ran and Iraq, officials were enthusiastic about the quality of satellite photos that helped them determine how the war was going.

Today's spy satellites like the KH11 have cameras that can take large overview pictures of a battlefield or zoom in on specific sections. The pictures are relayed instantly to receiving centers in the United States. In the old days, the film was parachuted out of the satellite and snatched out of the sky by a hook dragged by a transport plane.

Along with the ground war winding down, the Pentagon said yesterday, the strait of Hormuz seemed in no danger of being closed to oil tankers by either Iraq or Iran.

The Iranian navy continued to ask ships plying the Persian Gulf their distinations. If told Kuwait, Iranian ships made no effort to stop them.

The Iraqi and Iranian navies are so small that they would have difficulty blocking the strait, 30 miles wide at its narrowest point, Pentagon officials said.

The U.S. Navy continued its normal operations yesterday with no special alerts ordered in response to the Iraqi-Iranian war, according to the Pentagon.