Tony Blair: Princess Diana a 'Meteor' in the Royal 'Ecosystem'

Sept. 2, 2010— -- In an exclusive interview with "This Week's" Christiane Amanpour, former UK prime minister Tony Blair said he was worried about Princess Diana after her marriage with Prince Charles ended and she started dating Dodi Fayed.

"I was worried for her, frankly," Blair told Amanpour. "And I was worried because it was obviously going to be extremely difficult. And I wanted her to know, you know, what were the implications and consequences of all it was going to be."

In his new autobiography, Blair writes that Diana's relationship was creating some consternation. Her tense relationship with the royal family, which is well documented, had a big impact on her, Blair said.

Diana "was a kind of meteor coming into what had been a fairly well disciplined, well ordered ecosystem," he said. "And that obviously had a big impact on her with big consequence."

The former prime minister said it was difficult for him to convince the Queen of England to give a public address after Diana suddenly death in 1997, the year Blair became prime minister.

"Partly because of the loss, but partly because of the circumstances in -- in which she died, there was also a sense of anger. Now, some of that anger was directed at the paparazzi, but some of it, I think, was -- was directed at the establishment that people felt had let her down in some way," Blair told Amanpour.

"In the end, the queen did that (honored Diana), I think, magnificently," but he added that the task to talk to her was difficult. "It was difficult for me because I was a new prime minister and I didn't really know the queen. And, you know, it was -- I was very nervous in and around her, as you would be."

Blair's new autobiography, "A Journey: My Political Life," hits U.S. bookstands today. In the UK, it was No. 1 on Amazon UK's bestseller list even before it was released.

Watch More of Christiane Amanpour's Interview with Tony Blair tonight on "Nightline" tonight, and on "This Week" Sunday.

Blair took over the Labor Party's leadership in 1994 and spent three terms as prime minister, from May 1997 to June 2007.

From dealing with the conflict in northern Ireland to the invasions of Afghanistan and Iraq, Blair dealt with a wide array of domestic and international challenges, and took considerable heat from within his own party for many of his decisions, including his support for the war in Iraq.

"It's possible to have very difficult situations where you have difficult decisions and people disagree. And I think one thing is quite important in politics today, and your politics, my politics is -- actually, it's part of a modern democracy," he said. "It's to get to the point where people accept there are difficult decisions you can disagree with without hating each other or believing each other is badly motivated."

Blair writes candidly about his struggle with drinking, an activity that wasn't "excessively excessive" but that became "a prop."

"I was never quite sure, because sometimes it's a relaxation at the end of the day," Blair said. "As you get on with life you just need to treat it with care and be aware of its impact."

Blair said he gave up alcohol for six weeks earlier this year for Lent, an experience he called "interesting."