Is Osama bin Laden a rebel against the Saudi Arabian ruling class or a model member of it? That question lurks behind “The Bin Ladens,” by the Pulitzer Prize-winning New Yorker writer Steve Coll. The world’s most famous terrorist owes his fortune and his standing to a family business that Coll calls “the kingdom’s Halliburton.” Like Halliburton, the Saudi Binladin Group specializes in gigantic infrastructure projects. Government connections are the key to the family’s wealth. So you would assume they would react with unmixed horror to a radical son, like the duchess in the Noël Coward song:

You could have pierced her with swords

When she discovered

Her youngest liked Lenin

And sold the Daily Worker near the House of Lords.

But Saudi Arabia, Coll shows, is a place where the interests of rulers and revolutionaries are less easy to distinguish.

Muhammad bin Laden, Osama’s father, emigrated from the canyons of the Hadhramawt, in present-day Yemen, in the 1920s. He arrived in Jidda, one-eyed and semiliterate, at a time when Saudi Arabia had hardly any paved roads and the king kept his treasury in a tin trunk. Muhammad was charismatic. His workers, with whom he prayed and sang at job sites, revered him. He was scrupulously honest, as Arabian lore holds Hadhramis to be, and his company keeps this reputation still. Most important, Muhammad would serve the greedy and capricious Saudi princes in ways that Bechtel and other foreign contractors balked at  doing humiliating jobs from digging gardens to fixing air conditioners. The grateful royals made him their main palace- and highway-builder in the boom years after the war. By the time Muhammad died in a plane crash in September 1967, his company was worth an estimated $150 million, and he had fathered 54 children by about 22 wives.

Those children, Osama included, grew up in the shadow of a court society. Royal favor was all. Since the Saud family sent its sons to Princeton and Georgetown, Muhammad educated many of his own sons in the West, too, starting with Salem, his impious and ribald successor. Coll’s account of Salem is doting. When the austere King Faisal was assassinated in 1975, the sybaritic King Fahd took power. Hedonism and consumerism became for Salem what piety had been for his father: common ground with the royal family. Knowledgeable about private planes, luxury cars and new gadgetry, Salem became, as Coll puts it, a “royal concierge.”