Attacks on oil tankers in the northern waters of the Persian Gulf are a serious escalation of the Iran-Iraq war, but analysts do not expect a major problem with world oil supplies and prices as a result.
The latest incident was especially worrisome, since evidence suggests it was carried out by an Iranian jet. Previous raids have been traced to Iraq. But there is no evidence that Iran aims to go after shipping across the board, according to a State Department official. ''This was the first incident, and there is no indication that it is the beginning of a wave,'' the official said Tuesday.
In the short run, analysts say, any disruption of shipments from the northern end of the Gulf would have limited effect. Although oil prices have jumped on the speculative oil-futures market, they remain steady on the spot market, where oil is bought and sold for immediate delivery. Widespread availability of oil in the world today should keep the spot market fairly steady even if Iranian oil exports slow or Iranian prices increase to reflect the risk to ships calling at Iranian ports.
''These attacks are part of psychological war,'' an oil-industry source says. ''They are really just pinpricks at this point.''
If attacks on tankers increase - and if facilities such as refineries in countries along the western littoral of the Gulf are targeted also - the United States may have to reckon with a military as well as an economic response to the crisis. Middle East analysts have been concerned that the 44-month-old Iran-Iraq war might be coming to a head and that fundamentalist Iran might gain the upper hand. That would seriously affect the worlds of oil, Islam, and power politics.
This is the background against which the latest turn in the war should be seen. The recent attacks on oil tankers broaden the theater of war to waters well beyond the Kharg Island region. Iraq's aim apparently is to cripple Iranian exports and thus diminish Tehran's ability to finance its war effort. Iran, on the other hand, has vowed to close the Gulf to all oil exports if its shipments are curtailed.
The most recent tanker to be hit was the 18,012-ton Bahrah. It was the third to be attacked in two days after loading at an Iranian port, and the sixth in three weeks. Three of the others are still ablaze in the Gulf. Insurance premiums for ports in the northern Gulf have doubled to 2 percent of the ship's value for seven days' coverage, and rates may rise again. This, plus the risk to crews, is slowing exports from Iran's Kharg Island.
But the loss of Iranian oil is not of critical concern to the West. Iran exports only 1.6 million barrels of oil per day (b.p.d.). Japan has been the most important buyer, but Japan's needs could be met by other suppliers. The Japanese have decreased their liftings of Iranian oil by 150,000 b.p.d. since January.
Still, mindful of the Iranian threats to retaliate, a State Department official repeated the US position Tuesday that ''there is no military resolution'' possible for the Iran-Iraq war. The US has few diplomatic options, since Washington does not have full diplomatic relations with either Iran or Iraq. US ability to intervene militarily is similarly hampered.
''We have no facilities in the area,'' the official said. ''We'd be ill-advised to bring a naval force into that part of the Gulf.''
Nevertheless, the US is committed to keeping the Gulf open and to protecting Saudi Arabia and its Arab allies.
G. Henry M. Schuler, an energy specialist at Georgetown University's Center for Strategic and International Studies, notes that the Iranian attack on the Bahrah may have been meant to intimidate the Saudis. Mr. Schuler thinks Iran may be on the verge of a military breakthrough in the conflict.
''The Saudis,'' Schuler says, ''are looking across the Gulf, seeing a stronger, more intimidating Iran emerge.''
In a new study for Cambridge Energy Research Associates, William Quandt and Thomas McNaugher of the Brookings Institution note that short-term disruptions due to the war can be contained. The real threat, they say, comes not from continuation of the conflict ''but from an Iranian victory and the emergence of an Iranian-dominated coalition of oil producers. Out- and-out Iranian victory could decisively change the world oil market.''
The study notes three possible paths for the conflict:
* Maintenance of the balance of power - in which case oil prices, they say, could eventually fall.
* Iranian victory over Iraq and ''hegemony'' over the Gulf - in which case ''an Iranian-dominated coalition would thus become the swing producer for OPEC'' and oil prices might rise.
* A continuing war of attrition with occasional disruption of oil supplies - in which case shortages could be covered by higher production in other oil countries. The study estimates there are 10.6 million b.p.d. of unused oil capacity in the world.