LONDON, England (Reuters) -- U.S. President George W. Bush has alienated Muslims around the world by using absolutist Christian rhetoric to discuss foreign policy issues, former Secretary of State Madeleine Albright says.

"I worked for two presidents who were men of faith, and they did not make their religious views part of American policy," she said, referring to Jimmy Carter and Bill Clinton, both Democrats and Christians.

"President Bush's certitude about what he believes in, and the division between good and evil, is, I think, different," said Albright, who has just published a book on religion and world affairs. "The absolute truth is what makes Bush so worrying to some of us."

But Albright says Bush's religious absolutism has made U.S. foreign policy "more rigid and more difficult for other countries to accept."

In her book, "The Mighty and the Almighty," Albright recalls how Bush, while he was governor of Texas, told Christians he believed God wanted him to be president.

She quotes from his speech to his party convention of 2004, when he told Republicans: "We have a calling from beyond the stars to stand for freedom."

"Some of his language is really quite over the top," Albright told Reuters on Sunday during a trip to London to promote her book. "When he says 'God is on our side', it's very different from (former U.S. President Abraham) Lincoln saying 'We have to be on God's side.'"

She describes it as arguably worse than the Vietnam War -- not in terms of the number of people killed but because the Middle East is a more volatile region than southeast Asia.

She also bemoaned "the growing influence of Iran" in the region and warned sectarian violence between Shi'ite and Sunni Muslims could escalate into an all-out "Arab-Persian conflict."

"We should not be contributing to what is a long historical struggle between the Sunni and Shia," she said.