MANAMA, BAHRAIN, SEPT. 26 -- The American helicopter attack on an Iranian mine-laying vessel this week has bolstered the confidence of Arab states already working closely with Washington, but is less likely to change the cautious diplomatic attitudes of Arab leaders whose populations and national fortunes live within missile range of their large and bellicose neighbor.

According to a sampling of Arab and western diplomats in the region, the U.S. strike on the Iran Ajr was universally cheered in private by Arab leaders. Many were skeptical of Iran's peace-making intentions even as the Iranian president traveled to New York to address the opening session of the United Nations General Assembly.

But while the United States and western maritime powers enjoy widespread private support for their deployment of a 70-ship naval flotilla to protect shipping in the gulf, there is no consensus for an open break with Iran or a unified military stand on the Arab side of the waterway, officials said.

"We are waiting for one more attack by the Americans, if you can do it," said one Bahraini official, who said the attack showed "that no one can face America {militarily} in this region."

But another government official here said U.S. policy makers in Washington had demonstrated a fundamental lack of understanding of the revolutionary character of the Iranian regime and the inability of its religious leaders to compromise revolutionary objectives that have been articulated by Iran's spiritual leader, Ayatollah Ruhollah Khomeini.

"These people do not think as you do in the West," this official said, referring to Tehran's hierarchy. "And I'm afraid that won't change even after Khomeini is gone."

But most officials emphasized the positive impact of the attack in deterring military aggression by Iran against the smaller and militarily weaker Arab states of the gulf.

"The fact that there was somebody laying mines was a very definite threat," said Bahrain's minister of information, Sheik Tariq Moayyed, "and the fact that somebody stopped them was very positive. If you know that people are alert and will stop you, then you might think twice before doing it again."

In the short run, the U.S. military may wring additional concessions out of Oman, Bahrain, Saudi Arabia and Kuwait for joint use of air and naval bases. Some support has been provided for some time without public acknowledgement.

But, as Defense Secretary Caspar W. Weinberger told U.S. Navy crewmen aboard their ships anchored north of Qatar yesterday, "We need a lot more . . . and the allies coming in need more basing facilities, and we're trying to get all we can."

Weinberger said he expected the level of Arab military cooperation to improve in the next four to six weeks, and he based his confidence in part on the successful demonstration of U.S. military capabilities in thwarting the mine-laying mission of the Iran Ajr.

"The other Arab countries are basically very aware of what a danger Iran is to the civilized world," Weinberger said, "and they are all for what we're doing, and they're going to tell us that privately.

"But whether the {Gulf Cooperation Council states} or all of the Arab states will together condemn Iran or not, I don't know. They've come very close to it, much closer than they ever have before."

But converting secret military assistance on the Arab side of the gulf into a western-Arab alliance to isolate Iran and cut off its arms supply still appears a distant and unlikely prospect in Arab capitals, officials and diplomats said.

There has been a strong and persistent sense in the conversation of leaders of Arab gulf states that they will have to continue living with Iran long after the western fleets go home.

The American attack also may have raised some fears here that the United States has crossed a new threshold of escalation, beyond which Congress and American public opinion may not be willing to support. The willingness of U.S. forces to attack Iranian mine warfare forces, therefore, may not translate into an American response to Iranian aggression elsewhere in the gulf.

Since the Iranian-inspired violence in the Islamic holy city of Mecca in Saudi Arabia at the end of July, Arab League foreign ministers twice have rejected Saudi calls for a break in relations with Iran.

A meeting of the Arab League heads of state is scheduled for Nov. 8 in the Jordanian capital of Amman, and the subject of how to deal with Iran is high on the agenda. But as one senior Bahraini official put it, "Our hopes are high, but our expectations are moderate."

The fact of life for the Arab gulf states is that for the most part they must continue to profess in public their desire for a diplomatic solution that contains the militarism of both Iran and Iraq.

The intervention of the superpowers' and western navies, if it has done anything for them, has relieved them of the endless hand wringing over finding a regional or Islamic world solution to the seven-year-old war.

In one sense, the big powers are now the foil for the weakest states in the gulf neighborhood, who had pursued a policy of aiding Iraq in private until Iran resorted to military intimidation and internal subversion to punish them.

Ever in search of a safe haven, the oil-rich Arab states who have the most to lose from Iranian-backed threats on the Arabian Peninsula appear to be preserving their option to play peace makers with Iran -- but only after the American military has applied sufficient pressure to bring Iran to the table.