Royal tradition, a strong constitution honed in the deserts he loves and a stealthy cunning cloaked in rustic behavior are traits that enabled Abdullah ibn Abdulaziz to beat the odds and finally become head of the family business known as the Kingdom of Saudi Arabia.

The immediate conventional wisdom is that there will be little change in Saudi policy on oil, Middle East peace, Gulf security and the rest. That view is probably right, as far as it goes.

But do not think of the new king of Saudi Arabia as a totally predictable entity, or as someone not prepared to put his own stamp on things. The most remarkable characteristic King Abdullah has consistently displayed since I first met him in 1974 is his ability to learn quickly and to change slowly -- so slowly it can hardly be seen.

Back then some of his more sophisticated fellow princes considered Abdullah so impulsive, so rough-hewn and so affected by a serious speech impediment that they wanted him bypassed in the line of succession (in their favor, of course). They painted him to visitors as anti-American. He openly chafed at this treatment.

But somewhere Abdullah learned to wait, and keep his peace. For nearly a quarter-century he served as crown prince and chief executive officer to his half brother Fahd, who died yesterday after years of illness and incapacitation. Fahd had rallied to lucidity just often enough since a crippling stroke in 1995 to complicate Abdullah's running of the kingdom.

In that time Abdullah learned to use the language of diplomacy, to subordinate his intense anger at Israel -- and at U.S. support for Israel -- to the immediate security and economic needs of his country. He learned to argue with and outflank rivals at home and in Arab councils rather than smite them, even when his preferences were otherwise.

Do instincts that deep ever totally vanish? I have my doubts. With the shadow of Fahd finally lifted and his rivals now declaring fealty to him, Abdullah is free to be his own person more than most political leaders are, and more than he has been.

As monarch, Abdullah will certainly make serious efforts to work with President Bush and his aides, and with U.S. business.

But it will be easy for Washington to misread and mishandle this deceptively complex leader, who may be better at hiding still smoldering resentments and an intense nationalism than he has been at discarding them.

Although some three years younger than Fahd -- who was thought to be 82 -- Abdullah is in many ways less modern in his ways. As a young prince, Fahd traveled to peace conferences, Riviera casinos and Beirut bordellos while Abdullah was hunting with falcons in the desert and running the National Guard, whose main missions were to protect the royal family and the country's oil fields.

Fahd settled down after becoming crown prince in 1975. He set out to modernize the kingdom's economy and its diplomacy. In an interview in 1980 he told me that Saudi Arabia was ready to cooperate and live with Israel in return for complete withdrawal from the Arab territories occupied in 1967. Repeated by Abdullah in a separate interview then, that continues to be Saudi policy.

But poor health kept Fahd from ever making the throne a true center of power or reform. The military defeat of Iraq in 1991, the eclipse of the Iranian revolution and Egypt's turn inward had cleared the way for Saudi Arabia to step into a leadership role for the entire region.

That opportunity slipped away as the kingdom stood still, taking no more than baby steps on reform at home or in supporting the potential peace breakthrough that the 2000 Camp David summit represented. In that time, Saudi extremists such as Osama bin Laden intensified their war on the royal family and its American "sponsor." Fahd's reign will be marked as one of modern history's greatest missed moments.

Irony was not absent from the succession. Following the family tradition of restricting power to the sons of Abdulaziz ibn Saud, the kingdom's founder, Abdullah yesterday named his half brother, Sultan, crown prince and deputy prime minister. Sultan, who is 77, was one of those who had in the past questioned Abdullah's suitability to rule.

Abdullah has silenced those doubts and shown a taste for power. My bet is that he will not accept being a mere transitional figure but will leave his mark in ways that Fahd never did.