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."
Blair: No Apologies for Iraq Attack
The former prime minister is in the United States to participate in the Middle East peace talks. In the first direct talks in 20 months, Blair is representing the quartet that's involved in arbitrating a peace process between Israelis and Palestinians.
Blair expressed optimism about the peace process that has stalled numerous times, and praised President Obama for making it a priority right at the start of his presidency.
In his book, Blair writes that one of the biggest issues in solving that crisis is that no leader has gripped it for long enough or firmly enough.
The Bush administration "came to grip it, but it was late on in the presidency, and that's the important distinction with President Obama now," Blair told Amanpour. "I think you cannot overstate the importance of President Obama coming in and saying right from the beginning we're going to grip this, because that allows you, you see, to go through what will inevitably be the ups and downs."
Blair took considerable heat for supporting the 2003 U.S.-led invasion against Iraq, and becoming one of President George W. Bush's staunchest international allies.
Blair told Amanpour he feels an "enormous responsibility" for lives lost in Iraq. But he stood firmly by his decision to support Bush even though weapons of mass destruction were never found and the Iraq war led to a drain on resources in Afghanistan.
"You would be inhuman if you didn't regret the death of so many extraordinary, brave and committed soldiers, of civilians that have died in Iraq, or die still now in Afghanistan. And of course you feel an enormous responsibility for that, not just regret," Blair told "This Week's" Amanpour.
"But in the end, I believed and still do that if we left Saddam there, we would have had a different sort of problem, also with consequences and also with many people dying. So that's the difficulty for me, and likewise in Afghanistan," he added. "I think if we hadn't taken on the Taliban and hadn't taken on what had been a training ground for al Qaeda, we would be in trouble."
Hussein couldn't be contained, Blair argued, and even though it might have been better to focus on Afghanistan first, the former prime minister said world leaders couldn't take that risk.
Blair wouldn't rule out an attack against Iran if he was leading the country and was faced with the threat of Iran acquiring a nuclear weapon.
"I would tell them they can't have it, and if necessary, they will be confronted with stronger sanctions and diplomacy. But if that fails, I'm not taking any option off the table," he said.
"When you're a leader sitting in the hot seat having to take the decision, supposing your worst case materializes," and Iran acquires nuclear capability and then decides to use it, or share that technology with someone else, "Then what?"
Blair Calls Clinton His Political Soul Mate
Blair also defends former President Bill Clinton, who he dubs his political soul mate in the book.
"I think he was one of the first people really to understand, to articulate how progressive politics couldn't be a rainbow collation, that you had to stand up and be connected with people, not activists, simply," Blair told Amanpour. "And because in his concept of reinventing government, which he and Al Gore took forward, I think there's completely on the essence of the modern progressive politics."
The three-term prime minister praised Clinton "as one of the smartest politicians I've come across," and expressed confidence in Secretary of State Hillary Clinton leading the Middle East peace negotiations.
Clinton's two-term presidency was almost derailed because of his affair with Monica Lewinsky, an indiscretion that Blair wrote, "arose in part from his inordinate interest in and curiosity about people."
"Part of his genius [as] a politician is he is extraordinarily curious about people," Blair said today, adding that Clinton fared well through all the criticism.
"I came across him in some of the worst parts of all them impeachment business. I was talking earlier about the right get after you. Well, they were after him. And his ability somehow to refocus on the job and get it done," Blair said.
Blair also praised Hillary Clinton's negotiating skills, saying he is certain the secretary of state can confront all the challenges she is facing when it comes to international diplomacy.
"There is a lot on her shoulders. But she's completely capable of doing it," he said. "She's got the best type of political mind that knows where you meet the point of principle and knows where you need the subtlety and the compromise."
Blair is scheduled to receive the 2010 Liberty Medal from former President Clinton in Philadelphia on Sept. 13.
The former prime minister also sheds light on other American leaders, including former Vice President Dick Cheney who Blair says was "absolutely hard-line" when it came to matters of war.
"He thought the world had to be made anew and that after September 11th it had to be done with force and urgency," Blair writes in his book.
Bush, Blair said, was "straightforward and good to deal with."
"It's easy to mock that simplicity. And it's easy to ignore the strength that sometimes comes with that. And a decision like the surge in Iraq, you know, I can't think of many people who would have had the courage to take that decision in the way that he did," Blair said.