David Ottaway, a veteran of 35 years at the Washington Post, has found the perfect vehicle for his study of the U.S. and Saudi Arabia’s failed partnership. In The King’s Messenger, Ottaway focuses on Prince Bandar bin Sultan, the swashbuckling envoy who courted five U.S. presidents and 10 secretaries of state with a style of diplomacy so personal it evoked the Age of Metternich in Europe. But as Ottaway demonstrates in this richly complex portrait, if building a lasting bond with America was Prince Bandar’s goal, he was undone—maybe even doomed—from the start. His very success in forging a Saudi-American partnership, which resulted in a greater U.S. military presence in the Persian Gulf, would fan the resentment of Islamic fundamentalists and become a contributing factor in the 9/11 attacks. That cataclysmic event destroyed just about everything the prince had worked for.

We think of diplomats in the modern age as the products of formal, even antiseptic, educations. Prince Bandar was a bastard child, the result of a brief liaison between a powerful member of the ruling family and a 16-year-old household servant. Ottaway suggests, but does not document, that Prince Bandar’s struggle to gain recognition within the royal court (as a child, he played barefoot on Riyadh’s dirt streets) drove him to succeed. His proving ground was the Royal Saudi Air Force, in which he won a reputation as a daring stunt pilot. But more important, he received air force training in Britain and then the U.S. that would later prove crucial to his career.

On a flight home, in 1978, the 29-­​year-old squadron commander stopped briefly in Washington. President Jimmy Carter and Saudi officials all seemed to have decided that Prince Bandar could be useful in lobbying Congress to approve the sale of F-15s to Saudi Arabia, a transaction that Israel vigorously opposed. Though he did not get the official title until five years later, Prince Bandar would be the Saudi king’s ambassador for the next 27 years.

The seeds of the Saudi-U.S. partnership—Ottaway refers to it as a “special relationship”—had been sown during the anxious years of World War II. The partnership was in effect a mutual security pact, though the currencies on offer differed: The Saudis wanted arms; the U.S., oil. Though Ottaway does not quite say so, the partners badly misjudged each other. The Saudis warmed to the U.S. (and granted its oil companies preferential access) chiefly because America was viewed as less intrusive than the only viable Western alternative: imperialist England. The U.S. decided that socialism, not Islam, was the greater threat to its interests in the Middle East. As early as the Eisenhower era, when the Soviets were supplying Egypt with arms, the U.S. sought to bolster the Saudis as an Arab counterweight in the region. Later, when Russia invaded Afghanistan, the U.S. embraced Islamic fundamentalists as its natural allies.

Prince Bandar had no trouble making himself useful to the Yanks, whether he was persuading the Libyans to turn over terrorists, enlisting his king in the Palestinian peace process, or (according to his own account) helping persuade Mikhail Gorbachev to quit Afghanistan. Indeed, he seemed to have charmed almost everyone in official Washington and beyond.

When Carter sent Prince Bandar to persuade then-California governor Ronald Reagan to back the F-15 sale, the governor asked him only two questions: Was his country a friend of the U.S., and was it anticommunist? Ottaway recognizes that Prince Bandar frequently embellished his yarns, but the prince’s account of the Gipper’s simplistic policy analysis rings true. The F-15 saga is more disturbing for what it says about Carter: Why was a U.S. president employing a foreign national to help him with the U.S. Congress? Ottaway portrays Carter as so smitten with the dream of Saudi oil that it hijacked his foreign policy.