Detail from the cover of Bush's book Decision Points, which goes on sale Tuesday. Bush reveals that he almost removed then-vice-president Dick Cheney from the ticket before his re-election bid. (Reuters)

Former U.S. president George W. Bush's hotly anticipated memoir Decision Points reveals that he authorized the waterboarding of an organizer of the 9/11 attacks.

"He doesn't believe it was torture and he doesn't believe it was in contravention of any international charters," CBC reporter Susan Bonner told CBC News Network.

The book does not go on sale until Tuesday, but several U.S. news organizations have received advance copies and some key details have begun to leak.

Aside from Bush's personal hand in the waterboarding decision, other revelations include that Bush was stunned to discover there were no weapons of mass destruction in Iraq — the key justification his administration gave for launching the 2003 invasion.

Bush also writes that he considered removing former vice-president Dick Cheney before his second term because of Cheney's low popularity.

Cheney also angrily confronted Bush because the then-president did not pardon Lewis (Scooter) Libby, convicted of lying during the investigation into the leaked identify of CIA operative Valerie Plame.

Bush gives interviews

Bush has media appearances scheduled throughout the week to promote the book, starting with a pre-recorded interview with NBC's Matt Lauer that airs Monday evening. It's the 43rd president's first one-on-one interview since leaving the White House in January 2009.

In portions of the interview released by NBC, Lauer mentions that Bush believes it will be decades before any definitive conclusions can be made about his presidency.

Bush replies that his main purpose was to provide a "data point" for future historians.

"This may seem strange to you: I really don't care about perceptions at this point in time," he said.

It was already revealed last week that the former president believes the low point of his presidency was when rap star Kanye West said that "George Bush doesn't care about black people" in the wake of the government's slow response to Hurricane Katrina.

In the interview, Lauer asks Bush if he thinks he might be criticized for saying the low point was being insulted, not the suffering of the people in Louisiana.

"I also make it clear that the misery in Louisiana affected me deeply as well," Bush replies. "There's a lot of tough moments in the book."

One lighter moment has Canadian content.

New York Times columnist Maureen Dowd says Bush writes that he visited Russian leader Vladimir Putin, who boasted that his black Labrador, Koni, was "Bigger, stronger and faster than Barney," Bush's small Scottish terrier.

When Bush later told the story to Prime Minister Stephen Harper, Harper replied, "You're lucky he only showed you his dog."

With files from The Associated Press