Carmen Binladin, the terrorist leader's sister-in-law, says bin Laden's religious conviction was so admired by his family that she refuses to believe his relatives have stopped supporting him, as they claim.
In a new book and during an extensive interview with The Associated Press, she said a turning point in her life was a bin Laden family gathering in Taef, Saudi Arabia, one sweltering day in the mid-1970s.
Bin Laden's son began crying for water, she said, but the elder bin Laden refused to allow the baby to be given a water bottle, saying the boy should be fed water with a spoon because of Muslim teachings.
"It was not as if he didn't care about the child. But to him, the baby's suffering was less important than a principle which he probably imagined stemmed from some seventh-century verse in the Quran," Binladin said in her book, "Inside the Kingdom."
The respect her husband and Osama's 23 other brothers accorded him by accepting his decision helped persuade her to leave Saudi Arabia, Binladin says.
"From what I have seen and what I have read, I cannot believe that they have cut off Osama completely," Binladin said on the eve of a visit to the United States to promote her book, to be published in English on Wednesday.
She said some of Osama's sons are still in Saudi Arabia, working for the Bin Laden Group construction company, which the 25 brothers inherited from their father, Mohammed bin Laden.
"Osama is not the only religious (bin Laden) brother in Saudi Arabia," Binladin said. "And I cannot believe that some of the sisters (don't support him.) They are very close to Osama."
She said there might also be ties between Osama and the royal family, despite his criticism of the royals for their support of the United States and alleged corruption within the government.
"The bin Ladens and the princes work together, very closely," Binladen wrote. "They are secretive, and they are united. They have been inextricably linked for many decades through close friendships and business ventures."
Binladin married Yeslam, one of Osama's brothers, in 1974 and lived in Saudi Arabia for nine years. She said she wrote the book mainly to explain to her daughters why she had returned with them to Switzerland. Her divorce from Yeslam is still unresolved after 14 years.
The daughter of a Swiss father and an aristocratic Iranian mother, Binladin - dressed stylishly in a black leather jacket and jeans - spoke intensely with a French accent, smoking an occasional long, thin cigarette.
Her book has already appeared in 16 languages and 18 countries. But she said she had held off publishing it in the original English because of fears about how it would be received in the United States, where she lived for a time in the 1970s.
She and her estranged husband intentionally spell their name differently than the rest of the family and Osama. But she has been reluctant to revert to her Swiss name since leaving Yeslam, saying she does not want to appear like she is trying to cover up her past.
Her U.S. publisher is releasing the book under the name Bin Ladin, apparently to help readers recognize the name.
She said her time in Saudi Arabia gave her an understanding of the closeness of the bin Laden family, which lived in the 1970s clustered in a group of houses on the outskirts of Jeddah.
Women were required to wear a robe covering their faces and bodies whenever they went outside the home or encountered any males outside their immediate family.
"One day, Yeslam's younger brother Osama came to visit," she said in the book. "When the doorbell rang, I stupidly, automatically, answered it myself, instead of calling for the houseboy."
She said she recognized Osama and asked him in.
"But Osama snapped his head away when he saw me, and glared back toward the gate," she said.
He made rapid back-off gestures and waved her aside, muttering something in Arabic, "but I truly didn't understand what he meant."
A nephew with Osama explained that he was forbidden to look at her face.
She said she doubted accounts that Osama had been a playboy as a teenager in Beirut and thinks the story might have been about another brother.
"I never heard such tales about Osama," she said. "As far as I know, Osama was always devout. His family revered him for his piety."
Osama started putting his beliefs into action during the guerrilla war against the Soviet occupation of Afghanistan.
"According to his sisters, who spoke of him with awe, Osama was becoming a key figure in the struggle against the Soviet monolith," Binladen said.
"He imported heavy machinery, and manned earth-moving equipment to blast out tunnels through Afghanistan to house field hospitals for the fighters, and stocks of weaponry. He built dugouts to shield advancing Afghan warriors as they attacked Soviet bases. We heard that Osama had even taken up arms in man-to-man combat. Osama was making a name for himself."
When Iraq invaded Kuwait in 1990, Osama was outraged at the idea that U.S. forces might use Saudi Arabia as a base. He then started making "incendiary statements" against alleged corruption of the Saudi ruling family, and he was forced to leave the country.
She said none of the bin Laden sons measured up to their father, Mohammed bin Laden, who built a construction empire from the ground up.
She said she still keeps Mohammed bin Laden's photograph in her living room because she thinks her daughters deserve to know about their background.
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