Britain's former prime minister Tony Blair published his memoirs on Wednesday, saying he had no regrets over the 2003 Iraq war but stressing he was "desperately sorry" for those who died.
Entitled "A Journey", the book is Blair's account of his decade in Downing Street from 1997 to 2007 and also features an unprecedented attack on his "strange" successor Gordon Brown, whose premiership he brands a disaster.
It details the personal toll the job took on him -- including his use of alcohol as a "prop" -- as well as his role in the aftermath of princess Diana's death in a car crash in 1997.
However, it is Iraq -- arguably the defining event of Blair's decade in power --, which is at the book's heart.
Speaking of his feelings for all those who died in Iraq, he suggested he had wept over the death toll of British and international soldiers, ordinary Iraqis and other casualties such as hostages.
"Tears, though there have been many, do not encompass it," Blair wrote.
"I feel desperately sorry for them, sorry for the lives cut short... to be indifferent to that would be inhuman, emotionally warped."
But he insisted that he "can't regret the decision to go to war" as he again outlined the case for the conflict.
"All I know is that I did what I thought was right," he added.
Blair did, though, acknowledge that the period after the invasion was far worse than anticipated.
"The aftermath was more bloody, more awful, more terrifying than anyone could have imagined," he said.
"I can say that never did I guess the nightmare that unfolded, and that too is part of the responsibility."
He praised the "genuine integrity" and "political courage" of the then US president George W. Bush, with whom he stood shoulder-to-shoulder over Iraq.
And in a BBC interview being broadcast on Wednesday to publicise the book, Blair adds that the international community should be prepared to consider taking military action against Iran if it develops a nuclear weapon.
"I am saying that I think it is wholly unacceptable for Iran to have a nuclear weapons capability and I think we have got to be prepared to confront them, if necessary militarily," he said, according to pre-released extracts.
Blair also gave a series of candid insights on the "huge strain" life in Downing Street put on him, his wife Cherie and their four children, the youngest of whom was born while he was in office.
He used alcohol as a "prop" to relax and was "at the outer limit" of the regular intake limit advised by doctors.
"Stiff whisky or G & T (gin and tonic) before dinner, couple of glasses of wine or even half a bottle with it," Blair wrote, detailing his drinking.
"So not excessively excessive. I had a limit. But I was aware it had become a prop."
There is also a string of revelations about high-profile figures in Britain. Blair said he was a "sucker" for princess Diana but there was an emotional "wildness" to her which made him wary of her.
He also tells of "trying" visits to the royal family's Scottish retreat, Balmoral, and how Queen Elizabeth II would don rubber gloves to do the washing up after the royals' traditional barbecue there.
Elsewhere, he makes public as never before the private tensions which simmered between him and the "maddening" but "brilliant" Brown, who served as his finance minister, throughout his premiership.
Brown had long craved the top job and he and those close to him exerted increasing pressure on Blair to quit, particularly in his final years.
Blair said Brown was a "strange guy" with "zero" emotional intelligence. He said he knew that Brown's premiership would be "terminal" for the government.
"It is easy to say now, in the light of his tenure as prime minister, that I should have stopped it; at the time that would have been well nigh impossible," Blair wrote.
The former premier will donate all book proceeds to the Royal British Legion, a charity which helps severely injured war veterans.
According to reports, he has already received a 4.6-million-pound (5.6-million-euro, 7.2-million-dollar) advance.
The book is being published in English worldwide this week and translation rights have been sold to 17 territories.
Within hours of its release, online seller Amazon said "A Journey" was already ranked first on its British bestseller list.
Blair is in the United States, having been invited to a White House dinner by US President Barack Obama in his role as Middle East peace envoy.