JIDDAH, SAUDI ARABIA -- In almost 40 years of serving and ruling his country, Saudi Arabia's King Fahd has gained a reputation as a cautious man with little appetite for confrontation, a devotion to consensus and a tendency to procrastinate on difficult decisions.

But when Iraqi President Saddam Hussein rushed tanks to the Saudi border in August, Fahd had to adjust. Faced with what he believed was an imminent Iraqi land grab on his kingdom, he abruptly reversed its decades-long refusal to admit U.S. forces and called on Washington for massive help.

"Probably the biggest shock Saddam Hussein ever had was Fahd's decisiveness in a crisis," said a Western diplomat.

The consensus of those interviewed for this article is that while Fahd is slow to make major decisions, he sticks by them once made. As Washington's foremost Arab ally in the Persian Gulf, whose country may eventually host up to 400,000 U.S. soldiers, his ability to maintain that resolve will be a key factor in how the Persian Gulf crisis plays out.

Fahd had little choice in requesting U.S. military assistance; the alternative could have been to lose his independence to Iraq. But the decision was made on his watch as Saudi Arabia's fifth king, and in it, the 69-year-old monarch has taken the biggest gamble of his political life.

If the standoff ends with Saddam's peaceful withdrawal from Kuwait, Fahd's historic decision will be considered as having been necessary. But if it explodes into war, the king will have to deal with potentially destabilizing aftershocks: possibly thousands of Saudi, Iraqi and American casualties, destruction to his own country, and far-reaching political repercussions throughout the Arab and Moslem world.

Before the crisis is resolved, Fahd's personality and political leadership are likely to be tested as never before.

At first glance, the portly king seems an unlikely partner in the grim task of preparing for a military confrontation. Affable, chatty, unfailingly courteous and fond of telling stories, Fahd can while away hours playing cards with friends, doting on his children or helping his wife choose a new dress, according to those who know him.

His style is homey and down to earth. At the state dinner for Bush on his recent visit here, Fahd started up the evening's small-talk by extolling the nutritional value of yogurt and dates. Not a military man by nature or training, he prefers to boast to visiting diplomats of Saudi Arabia's advances in education and agriculture.

A night owl, Fahd sometimes works till dawn, as weary diplomats summoned for evening conferences have learned, and cabinet ministers get called at home in the middle of the night. Erratic and disorganized in his work habits, he can labor intensely for days, calling mid-level officials to see whether his orders have been carried out, and holding meetings, only to lapse into a prolonged period of inactivity.

Many of his subjects have long been puzzled by Fahd's tolerance for people who fail to perform up to standard. Some explain this away by noting his aversion to confrontation. "The king has a hard time saying no," one Saudi said.

An American who once asked a Saudi why the king did not fire some officials then targets of criticism for incompetence, was told: "The king has the worst chef in Riyadh! If he can't even fire his chef, how can he get rid of these officials?"

But there apparently are limits to Fahd's tolerance. Since becoming king eight years ago, he has fired three top officials, including oil minister Ahmed Zaki Yamani. None was considered incompetent, and a major factor appears to have been personal affronts to the king.

"People often think, because he speaks so nicely, that he's a soft one," said a long-time Western observer. "But he's tough."

One of president Jimmy Carter's Cabinet members reportedly experienced this. On a visit here, commerce secretary Juanita Kreps used her visit with Fahd to lecture him on why a cutback in oil production would not be appreciated by Washington.

"Fahd was very genial, and nodded his head and didn't say much," a former Carter administration official recalled. Kreps left the meeting and sent back "a glowing account" about how she had persuaded Fahd to keep oil production up. Unknown to her, the king summoned back the interpreter and dictated his own cable to the White House saying "he'd never been so insulted in his whole life and he didn't believe this was the president's message to him, and adding that he didn't want to be talked to like that ever again," the official said.

A prominent Jiddah resident who is closely concerned with royal activities said, "You can tell the king anything on two conditions: one, that it's tete-a-tete, in private, and two, that you tell him politely."

In a sense, Fahd's decision to call in American troops was an outgrowth of what has been the core of his foreign policy for decades: an enduring belief in the mutual benefits of a close relationship between his country and the United States.

The king has long been regarded as the most pro-American member of the royal family. He has maintained this stand despite repeated disappointments because of what Saudis perceive as a short-sighted unwillingness of successive U.S. administrations to exert more pressure on Israel for a resolution of its conflict with the Palestinians.

Despite widespread Arab opposition to the 1979 Camp David peace treaty between Israel and Egypt, Fahd was among the last of the Saudi ruling establishment to reject it. Staunchly anti-communist, he has also been willing to help Washington with clandestine financial support for pro-American groups, some far from the Arab world, such as UNITA, the U.S.-backed rebel faction in Angola.

This type of favor drew an embarrassed Saudi Arabia into the Iran-contra imbroglio after Fahd agreed to a Reagan administration request to help secretly fund the Nicaraguan contras when Congress blocked aid to them.

Fahd was born in 1921 to Abdul- Aziz ibn Saud, the Bedouin warrior who emerged from exile in Kuwait to create Saudi Arabia, and Hassa Sudairi, regarded by Saudi scholars as the most strong-willed and intelligent of his wives. As the royal family, the Sauds' mud-brick palace abutted the main mosque of Riyadh, but they were far from rich.

Fahd, the oldest of seven brothers and five sisters, was 11 when his father completed his conquests of outlying tribes and proclaimed Saudi Arabia an undivided state. He was still a teenager when American prospectors struck oil here in 1938, an event that led to a dizzying transformation of this poverty-stricken desert land into a petrodollar giant.

Early on, Fahd was groomed by his father for a job at the top. Family stories tell of how the young Fahd was assigned to sit for hours outside his father's council of advisers, waiting to carry out whatever clerical tasks were put to him.

In 1945, the 24-year-old prince made his first trip to the United States as part of the Saudi delegation to the San Francisco conference that wrote the United Nations charter. He stayed six months, taking away a lasting affection for California, according to a Western diplomat.

Named education minister in 1953, Fahd laid the groundwork for a modern education system that now includes seven universities. In 1962, he became interior minister, presiding over a period of insecurity for the kingdom as Egypt's fiery Arab nationalist, Gamal Abdel Nasser, lashed out at Saudi Arabia as "reactionary" and sent troops to aid anti-Saudi rebels in neighboring Yemen.

During these years, Fahd took long vacations abroad, reportedly enjoying the West's nightclubs, gambling, alcohol and pretty women. Those adventures ended after reprimands from his older half-brother, King Faisal, and Fahd began to prepare himself more seriously for the possibility of becoming king of this strict Islamic country.

He was named crown prince under King Khalid following the 1975 assassination of Faisal, and his stewardship of Saudi Arabia really began in earnest: Khalid was a reluctant monarch who assigned most of the day-to-day administration, as well as foreign affairs, to his crown prince.

In this post, Fahd oversaw the crucial years of Saudi Arabia's modernization, during which oil money poured in faster than beneficial programs for spending it could be devised. Fortunes were amassed by many, including the king; mistakes were made and corruption mushroomed. But many Western analysts credit Fahd with managing the kingdom's swift material transformation in a way that did not tear apart the fabric of Saudi political and social life, as it did in Iran.

"It's not easy to manage a boom of that magnitude," said Walter Cutler, a former U.S. ambassador here. "I think there was a very creative but firm guiding hand on that."

One reason Saudi Arabia's fantastic new wealth did not ruin its society was Fahd's insistence on maintaining a close alliance with the country's conservative religious elders. Although he is widely believed to favor faster change on such things as women's rights and establishment of an advisory council, he has taken a slower pace so as not to offend the powerful religious leaders.

But in a signal that he has no intention of yielding his authority to them, Fahd adopted the honorific, "Custodian of the Two Holy Mosques," sending out word this, rather than king, is the title he prefers.

In making decisions, Fahd consults several advisers, including his half-brother, Crown Prince Abdullah, and three full brothers, Prince Sultan, the defense minister; Prince Nayef, the interior minister; and Prince Salman, governor of Riyadh. He also turns to several friends outside the royal family for advice.

Although his brothers will tell him bad news others might not dare, many Saudis complain the king is no longer as accessible as he once was. His recent announcement that the government plans an overhaul of its administration, as well as the creation of a consultative council, is seen as a sign that Fahd is aware of this shortcoming.

While Fahd was said to be under "a lot of stress" in the first weeks after Iraq invaded Kuwait, he appeared relaxed and confident in a television appearance last week.

He is on the phone three or four times a day with his nephew, the Saudi ambassador to Washington, Prince Bandar, and the television sets at Salaam Palace are regularly tuned to Cable News Network. By most accounts, the Saudi king has banished procrastination and is working assiduously.

KEY DATES IN THE LIFE OF SAUDI KING FAHD

1923: Born Fahd ibn Abd al-Aziz Al Saud in Riyadh, the first of the "Sudeiri Seven" sons of King Ibn Saud and Hassa bint Ahmad al-Sudeiri.

1953: Becomes Saudi Arabia's first Minister of Education, responsible for the modernization of the kingdom's public school system.

1962: Named Minister of the Interior.

1967: Named second deputy prime minister.

1968: Named deputy prime minister.

1975: King Faisal is assassinated. Fahd is appointed Crown Prince and First Deputy Prime Minister to his half brother, the new King Khalid.

1982: Becomes king and prime minister upon Khalid's death.

March 17, 1990: Accords Saddam Hussein full honors when the Iraqi president visits Saudi Arabia.

July 19: Urges Iraq and Kuwait to settle their growing differences through negotiations.

August 6: Meets with U.S. Defense Secretary Richard B. Cheney four days after Iraq's invasion of Kuwait. Okays the deployment of foreign military forces to Saudi soil to protect the kingdom's security.

Sept. 6: Meets with U.S. Secretary of State James A. Baker III and pledges billions in aid to support the U.S. deployment.

Nov. 21: Meets with President Bush in Jiddah.

Compiled by James Schwartz -- The Washington Post