Monday's rounds of attacks and counterattacks in the Gulf have led to questions about where this round of hostilities will end. ``The implications are very serious and the mood is somber,'' says an administration official who requested anonymity.
US attacks against Iranian offshore oil platforms and warships have exacted retaliation for last week's mine attack on a US frigate, US officials say.
``We aim to deter further Iranian aggression, not provoke it. They must know that we will protect our ships, and if they threaten us, they'll pay a price,'' President Reagan said yesterday.
Whether there is further tit-for-tat fighting now depends on how serious Iranian officials view the damage done to their forces and prestige by US Navy weapons.
The Iranian regime may be feeling increasingly frustrated by strategic events of recent weeks, US analysts point out. For one thing, the so-called ``war of the cities'' has brought terror to Tehran. For another, little progress has been made this year infighting on the southern front of the land war with Iraq.
There were unconfirmed reports yesterday that Iraq has retaken the Faw Peninsula on the southern front of the land war. If true, this would represent a serious military setback for Iran.
Thus by strewing mines in the US Navy's path, and then by fighting back against US retaliation, Iranians are ``acting out some of their frustrations,'' says Frederick Axelgard, a Middle East analyst with the Center for Strategic and International Studies. ``They find themselves in a nasty frame of mind after the war of the cities.''
The rigs in the Gulf destroyed by US forces on Monday were the Sassan facility, described by the Pentagon as primarily a military platform for communications, radar monitoring, and small-boat operations, and the Sirri facility, which was used to monitor Gulf ship movements and pump oil.
By hitting these rigs the US was choosing the lowest rung on its ladder of military escalation. Iranian naval bases on Gulf islands, and military facilities on the Iranian mainland, would have been targets of more serious intent.
But since one of the rigs was still an oil producer, Monday's US strike hit cash-desperate Iran in a more sensitive spot than did last fall's US attack on two other Iranian offshore platforms.
``These were more important facilities,'' says Prof. R.K. Ramazani, a Middle East expert at the University of Virginia.
In addition, resistance led to US destruction of a 150-foot Iranian patrol boat, according to the Pentagon.
A larger Iranian frigate, which charged US ships and fired at circling US planes, was also bombed and hit with US missiles, leaving it heavily damaged and burning.
Details of any possible further damage and estimates of casualties to US or Iranian forces were unavailable in Washington at time of writing.
On Monday US officials were stressing that as far as they were concerned the round of fighting was closed. ``We consider that we have brought about proportionate retaliation,'' said Defense Secretary Frank Carlucci at an early morning briefing yesterday.
The US had adequate proof that the incident that sparked the retaliation - last week's mine attack on the USS Samuel B. Roberts - was the work of Iran, Secretary Carlucci said. Mines spotted near the spot where the US ship was hit carried Iranian serial numbers.
Intelligence information indicated ``that they were laid very recently, probably just in front of the passage of our ship,'' Carlucci said.
At the State Department, spokesman Charles Redman said that since last July the United States has sent Tehran four messages asserting that if Iran used mines in the Gulf the US Navy would respond. A message sent Sunday through Swiss auspices reiterated these warnings to Iran.
Before the attack, the US notified its allies who also have warships in the Gulf - Britain, France, and Italy - of the impending action, according to Mr. Redman. As the attacks began, the Soviet Union, Iraq, and other Gulf nations were notified.
A handful of congressional leaders were also informed of the US action before it occurred. House majority leader Thomas Foley (D) of Washington called the attack ``an inevitable consequence of the decision to reflag Kuwaiti vessels and to provide escorts.''
US military officers were uncertain as to whether Iranian resistance to the action was part of a concerted plan laid down by Tehran, or the result of on-the-spot decisions by local commanders. At least one of the Iranian ships sunk by US forces was not just caught in the middle of the fight, but steamed out of the port of Bandar Abbas to defend the oil platforms, according to the Pentagon.
Officers decline to speculate as to whether they now expect an Iranian round of retaliation.
``Let's just say we're busy,'' said one US officer.