Washington — A threat of spreading warfare looms over another part of the Mideast: the oil-producing Gulf. The delivery of new French Super Etendard warplanes to Iraq means a possible escalation of the Iran-Iraq war, American experts say.
The French are hoping that their aid to Iraq will restore some semblance of balance to a war that Iran appears to be winning. But the experts here warn that a ''worst case'' scenario - in which Iran retaliates against Iraq's big oil-producing supporter, Saudi Arabia, and other Gulf states - should not be ruled out.
If there is any comfort in the situation for the United States, it is that its rival, the Soviet Union, appears to have little more leverage over the parties to the conflict than does the US. Experts also tend to agree that the US has the capability, together with Britain and France, to reopen the Gulf to oil tanker traffic, should Iran close it.
The experts are divided as to how Iraq is likely to use its French planes, but they anticipate the opening of a new phase in the three-year-old Iran-Iraq war. One specialist, G. Henry M. Schuler at Georgetown University's Center for Strategic and International Studies (CSIS), argues that whatever the outcome of this new phase, Americans should intensify their efforts to reduce their dependence on imported oil.
Schuler agrees with others that Iran's ability to mine the strait or to attack the lower Gulf states by air strikes is limited. But he warns that one should not underestimate the Iranians' skill at commando raids nor their fanaticism. He adds: ''While we have the capability to keep the Gulf open, I'm not sure we have the political will to use that capability.''
Another specialist arguing against Western complacency is Anthony H. Cordesman, a former Defense official. Writing in the October Armed Forces Journal, Mr. Cordesman contends that the US has no choice but to continue to strengthen its Rapid Deployment Force and build an informal strategic partnership with friendly Gulf states. Cordesman says the Reagan administration is giving the RDF the priority it needs, and Gulf states have taken important defense initiatives.
The Saudi press agency said Wednesday that maneuvers being conducted by the GCC ''will provide more coordination'' among the armed forces of GCC member countries. The Saudi defense minister, Prince Sultan ibn Abdel Aziz, was quoted as saying, ''Iran has the right to make statements, and we have the right to self-defense.''
Meanwhile, Frederick Axelgard, a Middle East research associate at Georgetown University's CSIS, suggests that the United States could probably do more through its diplomacy to help shore up Iraq. Mr. Axelgard argues that the US and its allies must at all costs help to prevent Iran from dominating Iraq.
The Iraqis have contained the Iranian military threat, says Axelgard, but the great danger to Iraq is economic strangulation. After Syria shut the Iraqi oil pipeline to the Mediterranean last year, the Iraqis were able to export only a small percentage of their vast oil resources.
If Iran's Ayatollah Khomeini were not on the scene, the threat to the region would change markedly, with more moderate leaders coming to power in Iran, Axelgard says. But he argues that with Khomeini in power, Iran's war of attrition against Iraq is likely to be unrelenting.
''The Iraqis are trying to get the attention of the superpowers, especially the United States,'' says Axelgard. ''They are convinced that we can do something to end the war.''
Axelgard agrees with other experts that there are no easy solutions, and that US leverage is limited. But he says that by adhering rigidly to neutrality, the US has relegated itself to impotence.
US State Department officials argue that the US has no place but the sidelines.
''The Iraqis would like to have us perform a miracle for them,'' says one State Department official. ''But there is really no apparent, visible role for the US to play. . . .''
''The Iraqis got themselves into this mess,'' the official said. ''Now they are barely able to finance their war effort.''
Iraqi officials have informed the US that by acquiring new French warplanes, they are merely building the capability to do to Iran what Iran has done to Iraq: cut off its oil exports. The experts say this could mean an Iraqi attack on Iran's Kharg Island oil-exporting facilities.
Some experts say the Iraqis are just bluffing and that it would not be logical for them to risk triggering Iranian retaliation in the Gulf. But logic seems to have played little role in a war which, by US estimates, has cost the two sides together as many as half a million lives.