ABU DHABI, UNITED ARAB EMIRATES, JULY 28 -- Leaders of the Arab sheikdoms that line the southern Persian Gulf have expressed alarm over Iran's newest threat: to hit economic targets, possibly including offshore oil installations, in the event of an escalation in the gulf war.

Some United Arab Emirates oil platforms near the mouth of the gulf are being fitted with Swedish laser-guided antiaircraft missiles, according to western sources, raising fears in their large foreign work force that the heavily defended oil rigs are becoming military targets that might invite attack.

American oil companies have pulled their crews from some oil rigs that are being armed by government security forces, the sources said.

Iranian President Ali Khamenei, parliament speaker Ali Akbar Hashemi Rafsanjani and, today, Ayatollah Ruhollah Khomeini have stepped up their harsh criticism of U.S. military involvement in the gulf and threatened retaliation toward countries that ally themselves with Iraq, Iran's opponent in the seven-year-old war.

Meanwhile, Kuwaiti officials said today that the U.S. Coast Guard has informally told Kuwait's state oil tanker company that it can begin loading crude oil into the mine-damaged supertanker Bridgeton in an effort to prepare it to move at least a partial cargo through the treacherous waters of the Persian Gulf by the end of the week.

The sudden alarm about Iranian retaliation follows moves in which Iran has appeared to pass beyond thresholds of escalation that western governments thought it would not cross.

"Prior to May 6," said one western ambassador in the area, "the assumption was that Iran would never hit a superpower." On that date a mine suspected of having been placed by Iran damaged a Soviet oil tanker.

Then last Friday, another mine damaged the Bridgeton, the first Kuwaiti supertanker reflagged as an American vessel, as it steamed up the gulf under heavy U.S. Navy escort.

The intervention of U.S. naval forces in the gulf to protect Kuwaiti shipping apparently has prompted Iran to escalate its threats. Speaking Friday in Tehran, Rafsanjani declared a "new policy of retaliation." The official Iranian news agency has described the new policy as this: "If Iranian economic centers and installations are attacked, Iran will strike at economic centers of Iraq's allies." Rafsanjani added yesterday that the retaliatory attacks would be limited to the Persian Gulf waters.

Khameini was quoted by Tehran radio last night as saying that if Kuwait continues "mischief" in the gulf, Iran would retaliate with surface-to-surface missiles.

Today, Khomeini warned "all the eastern and western superpowers and especially America and Russia" against "interference and adventurism." He said Iran and "Moslems the world over" should "be determined to crush America's teeth in its mouth."

These threats have been taken as a grave warning in these emirates that Iran could well turn billions of dollars worth of highly vulnerable Arab installations into infernos in its campaign against support for Iraq.

Largely untouched by the conflict, these emirates have in fact prospered during the war by offering crude oil at premium prices to customers who do not want to send their oil tankers through waters made dangerous by Iran.

They have supported Iraq out of Arab solidarity and as members of the Gulf Cooperation Council, but have maintained their strong trade and cultural ties to Iran.

"All of the wealth of Dubai is based on commerce with Iran," one western official said.

But the delicate -- and profitable -- balance of relations between the southern gulf states and Iran is in immediate jeopardy, according to western officials here.

Western diplomats said that, in the face of the Iranian threats, the sheiks of the southern gulf are surveying the vulnerability of their offshore network of oil fields, pipelines and tank farms, which could become what one western diplomat described as "ground zero" for Iranian retaliation for renewed attacks by Iraq.

"We're in a completely new ball game if these rigs and offshore facilities become targets," said one western diplomat. "You can't defend an oil rig from aerial attack, and there are hundreds of rigs out there."

Last November, three French technicians were killed when Iran bombed an oil platform operated by Abu Dhabi's national oil company.

European diplomats have told their home offices that the further isolation of Iran and military buildup in the gulf put the southern gulf's oil complex in greater jeopardy.

This poses a special problem for some countries. The British Embassy here has expressed urgent concern about the safety of 300 Britons working at the United Arab Emirates' large offshore complex at Das Island. A single hit at the liquefied natural gas storage tanks there, western sources said, could set off an explosion that would kill hundreds of workers.

These officials point out that many of the oil fields of the southern gulf are interconnected. Iran and the United Arab Emirates' sheikdom of Sharjah share oil production facilities on the island of Abu Musa, another suspected base for Iranian speedboat attacks against shipping.

Iranian helicopters have reportedly used abandoned oil rigs in the Sassan oil fields near the mouth of the gulf as bases for their aerial attacks against shipping.

"The Arabs here don't want a confrontation with Iran and they don't want Iran isolated," said one western diplomat. "They just want the war to finish because it is now getting too dangerous for them and they don't want the whole gulf to explode."