WASHINGTON is watching closely as one of its most stable Arab allies enters a season of change.
The desert kingdom of Saudi Arabia has long been a pillar of American interests in the Middle East, a conservative but moderate Islamic state that in recent years has helped maintain stable oil prices and even given cautious support to the US-backed Arab-Israeli peace process.
But mounting financial woes stemming from declining oil prices, reckless spending, and the 1991 Gulf war - plus restive Muslim fundamentalists - have afflicted a nation that once used oil profits to hold adversity at bay. Now, with the country's monarch at least temporarily indisposed, the kingdom's aging leadership is in transition.
In the short term, a coincidence of US and Saudi interests in maintaining a strategic alliance to deter threats from the dominant military powers in the Gulf region - Iran and Iraq - seems unshakable.
Over the long term, King Fahd's recent decision to hand the reigns of power to his half-brother, Crown Prince Abdullah, has implications that are less clear. Power was transferred Jan. 1.
"There's nothing to worry about now, but how is it going to pan out if Abdullah becomes king?" asks one expert on Saudi Arabia who requested anonymity. "In the worst case, it could lead to increased uncertainty in the US-Saudi relationship."
The crown prince is one of 25 surviving sons of Abdul Aziz (Ibn Saud), who established the Saudi kingdom in 1932. To become king, Abdullah would need the approval of his 24 half-brothers, some of whom consider him, at age 72, too old for the job. One possible alternative: the popular, capable, and younger Prince Salman, the governor of Riyad.
As head of the country's 57,000-man National Guard security force, Abdullah is used to working closely with American military advisers.
But he is described as less reflexively pro-American than King Fahd and, to a degree, less supportive of Middle East peace moves. In a speech last October he declared that Jerusalem - which Israel claims as its capital - should be an Arab and Islamic city forever. The comment was not warmly received in Washington.
But State Department spokesman Nicholas Burns said last week that it was "absolutely untrue" that the US regards the crown prince as "anti-Western, anti-American, and anti-peace with Israel."
Analysts speculate that for health reasons Fahd may not return to power, meaning that Abdullah will reign as de facto monarch until Fahd dies or formally abdicates. Without the full authority of a de jure monarch, they say, Abdullah could have a harder time arbitrating disputes among members of the royal family.
Even as the future of the monarchy grows clouded, the restiveness of Muslim militants appears on the increase. Last November, Islamic elements were suspected of planting a bomb that destroyed a facility in Riyadh, the Saudi capital, where Americans were training Saudi military personnel. Six people were killed and 60 others injured in the blast, triggered by a car bomb.
The incident caused jitters in Saudi Arabia and other Gulf countries where the US has based troops or equipment to deter a repetition of Iraqi aggression. In 1990, Iraqi troops invaded Kuwait and threatened Saudi Arabia. Saudi Arabia was used as a launching pad for a US-led war to expel the invading Iraqis.
Some 12,000 US military personnel are now stationed in - or afloat near - Saudi Arabia and other Gulf countries. The US has also based a new Fifth Fleet in Bahrain to patrol the Gulf and the Indian Ocean.
Though little is said publicly by the royal family about close US-Saudi military cooperation, it remains the precondition to Saudi security.
"The senior Saudi leadership hates the Iraqis for their treachery and realizes that the only way to meet potential new threats is to make it clear to Baghdad and Tehran that if they misbehave, they'll get thumped by the US quick and hard," says Simon Henderson, the London-based author of a recent book on Saudi Arabia entitled "After King Fahd."
But experts say the arrangement under which Saudi Arabia provides cheap oil and the US provides the security umbrella needed to get it to market may not be a permanent feature of the relationship.
"If Abdullah thought there was a better way of earning more oil revenues - either by increasing exports and getting greater market share, or by decreasing exports and hoping the shortfall would not be made up by other exporters - he would do it," says Mr. Henderson.
In the US, meanwhile, pressure to reexamine the cost of Gulf security is likely to grow in sync with pressures to trim the Federal budget.
The US spends $50 billion annually to secure the free flow of oil from the Gulf, but imports only $11 billion worth of Gulf oil each year. Even if oil prices jumped $15 per barrel, the US would still be paying more than it gets. All of which has prompted some Middle East experts to ask whether the nations that need Gulf oil the most, notably those in Europe and Asia, should not pick up a larger share of the tab for keeping the Gulf region secure.
"The $50 billion has to come at the expense of social programs," notes Shibley Telhami, director of the Near Eastern Studies Program at Cornell University in Ithaca, N.Y., and currently a guest scholar at the Woodrow Wilson International Center for Scholars in Washington. "As people begin to realize this, the [Gulf] military budget will no longer escape scrutiny.
"We're entering a phase of rethinking based on self-interest," Mr. Telhami adds.