US naval attack: Will retaliation lead to escalation? The US retaliation against Iran has muted congressional debate over the War Powers Resolution, as lawmakers presented a united front with the administration (Page 3). US allies also supported the attack (Page 32).

By destroying an offshore Iranian oil facility with a rain of naval gunfire, the United States has inevitably increased its military role in the Gulf. The question now is whether Tehran views the leveling of its oil platforms by 1,000 five-inch shells as a slap that must be answered - or a symbol of will that means the US tanker-escort operation should not be directly challenged.

In describing the attack on Monday, Reagan administration officials took pains to play down the possibility of further escalation in what is becoming a direct US-Iranian conflict in Gulf waters. Destruction of the two-platform Rostam (also called Rashadat) oil facility was a proper and measured response to last week's missile attack by Iran on a US-flag tanker, said Defense Secretary Caspar Weinberger.

The facility's two platforms were a military target, not an economic one, Secretary Weinberger said. They had not pumped petroleum in over a year and were being used by the Iranian military as a base for speedboat attacks and observation of US convoy operations.

``We consider this matter closed. We do not seek any further confrontation with Iran,'' said the secretary of defense.

Directly after last week's Silkworm missile strikes against oil tankers in Kuwaiti territorial waters, administration officials talked as if no US response would be forthcoming. They noted that the US escort operation does not officially extend into Kuwaiti territory.

Such statements by Secretary of State George Shultz and others may have signaled genuine reluctance - or they may have been a feint. The US Gulf convoys have been undertaken at Kuwait's request, and one of the ships struck by a Silkworm was the Sea Isle City, a Kuwaiti vessel now flying the US flag. If the US military presence were to have any meaning at all, retaliation was inevitable, according to a number of Middle East analysts.

Kuwait, Saudi Arabia, and other conservative Gulf states reportedly strongly urged the US to hit back.

``Something had to be done,'' says Shaul Bakhash, a history professor at George Mason University.

Thus, the fact that there was an attack came as no surprise here. On Sunday, President Reagan himself had hinted that some such strike was coming. The only questions were where and when.

The primary option was widely assumed to be a strike by warplanes from the carrier USS Ranger, in the north Arabian Sea, against Silkworm missile launch sites on Fao Peninsula in Iranian-occupied Iraq. But several factors ruled against hitting the Silkworms, analysts say.

For one thing, the missile launchers are mobile, and thus may well have been packed up and hidden in the desert. For another, Fao is at the north end of the Gulf, far from the Ranger's position, and an air strike would have been a complicated military operation. It would have necessitated in-flight refueling, and perhaps direct involvement by Saudi Arabian and Kuwaiti support planes.

Shelling Rostam, a platform more than halfway down the Gulf and 120 miles east of Bahrain, was therefore a much easier operation. No US pilots were risked; no US Gulf allies were compromised by appearing to lend aid.

``The administration action was wellcrafted in that respect,'' says Frederick Axelgard, an analyst at the Center for Strategic and International Studies.

But Mr. Axelgard also notes that the destruction of Rostam, from a military point of view, is to Iran only a ``minor nuisance.''

The two platforms of the facility (a third rig had already been destroyed by Iraqi warplanes) were used for speedboat attacks and observation of US tanker convoys, Mr. Weinberger said on Monday. A US helicopter had been fired upon from Rostam on Oct. 7, according to the defense secretary.

Rostam's military functions can easily be replaced. They can be run from other oil rigs, Farisiyah Island near Kuwait, or from Abu Musa, islands Iran has fortified near the Strait of Hormuz.

In addition, US forces made an effort to lessen Iranian casualties, broadcasting a warning that an attack was forthcoming 20 minutes before four US destroyers used Rostam for 90 minutes of marksmanship practice.

Thus it seems clear the Reagan administration's purpose in its choice of target was not to hurt Tehran, but to send it a graphic message, analysts say. Pounding an oil rig with 1,000 shells, after all, likely results in physical obliteration.

``We will be fully prepared to meet any escalation of military actions by Iran with stronger countermeasures,'' said Weinberger on Monday.

[Iranian radio reported Monday that two oil facilities 30 miles apart had been attacked by the US Navy, and an unspecified number of civilian crewmen wounded. A government spokesman vowed a ``crushing response.'']

But will Iran be intimidated by US Navy gunfire?

A battle-tough country already convinced that the US has sided with Iraq in the Persian Gulf war, Iran is unlikely to slink off meekly into the night, according to Middle East experts.

So far, as the Silkworm attacks and the sowing of mines in Gulf waters demonstrate, the Iranians have been clever at finding small chinks in the armor of US forces.

``It's illogical to not expect some sort of response,'' says Professor Bakhash.

But whatever happens the US now seems locked into its presence in the region, and thus may be forced to engage in a response-counterresponse game.

A team of analysts from the Senate Foreign Relations Committee, in a report released Sunday, say that, after a recent tour of the Gulf region, they believe that the US commitment to protect Kuwaiti tankers ``could be reversed only at great cost to US credibility in the region.''

US friends such as Saudi Arabia suspect that the US will cut and run when the going gets tough, says the report. At the same time, the conservative Gulf states criticized the high profile of the US reflagging operation, according to the committee aides.

``Why do you Americans have to do this sort of thing with so much fanfare?'' said one Gulf nation official quoted anonymously in the study.