The Next Crusade.(Paul Wolfowitz)

The Selimiye Mosque, in Edirne, a city in northwest Turkey, is a magnificent stone edifice, with four minarets and an austere, octagonal-shaped body supporting a large dome. Built for Sultan Selim II in the sixteenth century, it has withstood numerous earthquakes and can accommodate more than five thousand kneeling worshippers. One evening at the end of January, I visited the mosque with Paul Wolfowitz, the president of the World Bank, and a half dozen of his aides and colleagues. Two years have passed since President Bush nominated Wolfowitz, the former Deputy Secretary of Defense and one of the architects of the war in Iraq, to head the sprawling multinational lending institution that has as its official goal "a world without poverty."

The World Bank employs thirteen thousand people in more than a hundred countries, and lends about twenty-five billion dollars a year to poor and middle-income nations. When Wolfowitz inspects bank programs, he often visits religious sites and other monuments. At the Selimiye Mosque, a stern-looking young man with a black beard who identified himself as the imam met us at the entrance and invited us inside. After putting on slippers, Wolfowitz entered the mosque and listened as the imam, demonstrating its acoustics, raised the call to Allah.

Wolfowitz has an abiding interest in the Islamic world. His father, Jacob, an eminent mathematician who taught at Columbia and Cornell, was a fervent Zionist, and Wolfowitz's elder sister, Laura, lives in Israel. Wolfowitz's critics sometimes portray him as an unquestioning defender of the Israeli government, and yet he has publicly expressed sympathy for the plight of the Palestinians, and some Arab reformers regard him as a friend. Since separating from his wife of more than thirty years, Clare Selgin Wolfowitz, in 2001, he has dated a secular Muslim woman in her fifties, Shaha Ali Riza. A British national from a Libyan family who grew up in Saudi Arabia, Riza is a longtime advocate of democracy in Arab countries.

On a wall of the mosque was some ornate writing in Arabic. "Is that the Fatiha?" Wolfowitz asked, referring to a passage in the Koran. No, the imam replied, explaining that the writing was from another passage. Wolfowitz taught himself Arabic in the nineteen-eighties, when he was working at the State Department. (He also speaks French, German, Hebrew, and Indonesian.) Last year, during a visit to a mosque in eastern China, he recited a prayer from the Koran in Arabic. This time, as he was leaving the mosque, he encountered a dozen or so news photographers who had gathered to document his visit. Bending down to change back into his shoes, Wolfowitz removed a slipper, revealing a large hole in the toe of one gray wool sock. Then he removed the other slipper, exposing another hole. Shigeo Katsu, the World Bank's vice-president for Europe and Central Asia, tried to step between Wolfowitz and the photographers, but it was too late. The camera shutters clicked.

If Wolfowitz was perturbed, he didn't show it. He went next door to a covered market, where he examined the religious and cultural icons for sale. One of the venders urged him to buy some jewelry, but Wolfowitz didn't have enough cash. His spokesman and senior adviser, Kevin Kellems, gave him what he had, about seventeen dollars in Turkish lira. "I'm going to need more than that," Wolfowitz whispered. A member of the bank's Turkish staff handed him a hundred lira (about seventy dollars), and Wolfowitz bought two silver bracelets, for his daughters.

Wolfowitz, who is sixty-three, has jug ears, hazel eyes, a furrowed brow, and thinning gray hair that he combs to the right. He is a rumpled but unflappable traveller, seemingly oblivious of bad weather, uncomfortable transportation, and lack of sleep, as well as of the antiwar protesters who tend to appear wherever he goes. Since joining the World Bank, Wolfowitz has visited more than fifty countries, including remote parts of Africa and Asia. He is often depicted in the media as a neoconservative zealot, but on the road he is unfailingly polite, demonstrating a scholarly interest in local culture.

In Istanbul that morning, Wolfowitz had visited a homeless shelter run by the Turkish government with financial assistance from the World Bank. The shelter was in a nineteenth-century neighborhood, in a brick building on a cobbled street. After greeting the shelter's director, Wolfowitz and an interpreter entered a small room, containing four narrow beds and some metal chairs. Wolfowitz sat down next to a slight middle-aged man in a fraying denim jacket and a black wool cap, who said that his name was Bedir Yasa and that until recently he had been living on the streets.