With Iran reeling after a series of bloody defeats on the battlefield, Pentagon experts believe conditions are ripe for an end to the 8-year-old Gulf War.

The long war has sapped Iran's will and ability to fight, they say, and Iraq has effectively driven Iranian forces out of its territory for good. While the peculiar politics of the Islamic Republic make it unlikely the war will end suddenly, the recent string of Iraqi victories could set the stage for a truce or peace treaty within the year.As the Ayatollah Khomeini's health and the Iranian economy deteriorate, infighting among religious factions over the succession and public discontent with the war have distracted the Tehran government's attention from the front.

"There are enough (domestic) problems . . . and the military situation's bad enough that it's quite conceivable to me that you could have some kind of resolution of this thing in the next year," said a defense official with wide experience in the Gulf region. "But what you're looking at is a kind of window of opportunity here before the Iranians begin to recover, maybe three or four months."

Late last week Iraqi forces seized the oil-rich Majnoon islands in southern Iraq, capby Iran in 1984. Details of the fighting were sketchy Sunday, but Pentagon experts said last week Iraq had mounted an overwhelming force of troops, tanks and artillery opposite Iranian positions in Majnoon.

While the latest action essentially restores all of the territory Iraq lost after its abortive attack on Iran in September 1980, experts don't expect the Iranians to sue for peace immediately.

Richard Armitage, assistant secretary of defense for international security affairs, says even if Khomeini dies soon his successor will have to follow his hard line on the war at first.

"As the ayatollah's health declines . . . the pretenders to the throne are going to have to be at least initially holier than thou, consequently they may even be . . . more radical in their behavior until the leadership situation sorts itself it out," he said. "So I don't particularly see any amelioration of policy coming before the death of Khomeini or immediately after the death." But the Iranian public has grown war-weary, Armitage says, and opposition is spreading.

"There are demonstrations in more places, albeit there are a limited number of people taking part in the demonstrations, and in many cases force has to be used to bring them under control," he said. "Ultimately whoever succeeds Khomeini is going to have to deal with it."

Another official, who spoke on condition he not be identified, said Iran has suffered grievously in a series of Iraqi attacks. Although casualty figures are imprecise at best, estimates of Iranians killed in Iraqi assaults on the Faw peninsula and at Fish Lake since mid-April range as high as 33,000. Given the strong force that assaulted Majnoon, Iranian losses there are likely to have been heavy as well.

Iran also lost scarce military equipment in the recent battles that it will be hard-pressed to replace.

"At Faw they lost 50 tanks and 75 artillery pieces and (they had) similar kinds of equipment losses at Fish Lake," the defense official said. "At Fish Lake they evidentally ran off and left three complete battalions of artillery in place on the battlefield."

Equipment losses over the past eight years have left Iran in the unenviable position of facing roughly 3,000 Iraqi tanks in the south with only about 50 of their own.