With the late afternoon sunlight making a last gasp into his Washington DC apartment, Christopher Hitchens, one of America's most prominent journalists and provocative authors, tries to ignore the minor commotion of President George W. Bush's motorcade passing the streets below.
Without pausing, Hitchens, a British-born American citizen, proceeds to finish his story about that devastating early September morning in New York more than six years earlier.
"It irritated me that the President, standing not far from the rubble of the Twin Towers, said that you're either with America or with the terrorists," Hitchens recalls as he describes walking through the badly shaken streets of lower Manhattan, his first American home, scanning the countless missing persons posters.
"The President described it as an attack on America. I would prefer to say that it was an attack on civilisation."
For Hitchens, 59, the events that day were part of what he calls a series of "test moments" - periods when one's ethical beliefs are placed on trial by external challenges or crises.
Channelling one of his influences, George Orwell, Hitchens viewed the terrorist attacks in New York, Pennsylvania and Washington DC as a moment to respond - which he did, by becoming an advocate for the invasion of Iraq, a move leftist critics saw as opportunistic and imperialist.
Hitchens wrote a series of columns for Vanity Fair and the Nation after the attacks that revolved around his disgust for the perpetrators while saluting the stoicism of New York City that he claimed harkened back to the "British phlegm during the Blitz".
Since 9/11, Hitchens has employed an aggressive rhetoric over what he has called "Islamofascism" or "fascism with an Islamic face".
"There was a time when you could publish a book that said 'Muhammad sucks' as long as you were not and never had been a Muslim," Hitchens said. "Now you can't. The aggression [of fundamental Islam] is mounting all the time.
"And I'm very, very determined that this does not go unchallenged."
In late 2002, Hitchens resigned from his position at the Nation after writing that the publication had become "the echo chamber of those who truly believe that John Ashcroft [former US Attorney-General] is a greater menace than Osama bin Laden".
Moving even further away from the liberal left, Hitchens began his unwavering support for US military intervention.
"Shall I take out the papers of citizenship?" Hitchens wrote in Vanity Fair in December 2001. "Wrong question. In every essential way, I already have."
Recalling 9/11 today, Hitchens attempts to place it in a larger history of "test moments" - which include the death sentence placed upon his friend, the novelist Salman Rushdie, by the Ayatollah Khomeini and the ethnic cleansing in Bosnia.
"There's a poem by I forget whom [the poet Robert Lowell] with a line that says 'To every man and nation comes the moment to decide'.
"It's a time when you look around at people and you think 'it really matters to me what you say now. I want to know, without any ambivalence, where you stand, what you think'."
Hitchens leaves no doubt where he stands and what he thinks with his blistering critiques of well-known figures including Mother Theresa, Bill Clinton and former Secretary of State Henry Kissinger.
Last year, he took on religion with God is Not Great: Why Religion Poisons Everything. His prose bristles with contempt for its dogma and its association with violence across the globe from Northern Ireland to Beirut.
On this day, relaxing with a post-lunch espresso, Hitchens' opinions pour forth. Perhaps it is just the typical eclecticism, but the conversation flits from memories of New Zealand - he fondly recalls meeting David Lange and visiting the West Auckland vineyards - to caustic indictments of many things and many people.
For a few moments, Hitchens turns his full attention to the presidential race. Hillary Clinton is "full of ****". He thinks that Michelle Obama and her "terrible" speeches will undoubtedly become the target of another Republican "swiftboat campaign" to derail husband Barack Obama.
However, it is Republican nominee John McCain who receives the full brunt.
"You look at McCain's swollen, senile face with his glassy eyes. And it's only ****ing May - what's he going to be like in January when he takes the oath - and that's the beginning of four years. All the say is 'age could be an issue'. No - he's senile. He's coming apart before our eyes."
Geo-politics is up next. Comparing the hurried, colonial construction of Israel and Pakistan, Hitchens argues that the latter is "a partly rogue, partly failed state. Pakistan is not a real country. And I must say that I feel the same when I go to Israel."
Hitchens shares his beautiful, if somewhat stark, apartment with his wife, the journalist Carol Blue, and daughter Antonia (he has two children from his first marriage to Eleni Meleagrou, a lawyer who lives in London).
Born into a military family on April 13, 1949, a birthday he shares with Thomas Jefferson (about whom Hitchens penned a short book in 2005), Hitchens' fascination with history and politics was piqued at a young age.
"I was brought up on navy bases in England and in the Mediterranean at a time when - we thought - the British Empire was all gone forever."
He went to Oxford then to a job at the New Statesman.
Working in London in the mid-1970s during the height of the IRA's bombing campaign, Hitchens also had his first taste of war reporting - a subject that would be the fuel of a great deal of his later journalism.
"The first breaking story I ever covered as a reporter was in Ulster. And the first time I saw any violence or any war was in my own country. "
He moved to the United States in the early 1980s. For some time, the popular image of Hitchens as the hard-drinking, heavy-smoking, swaggering, globetrotting journalist has rivalled the attention given to his journalistic output.
He still enjoys a drink - sipping on a scotch in the early evening, he claims "alcohol is a good friend but a bad master". He has cut down his daily intake, which he once wrote was enough "to kill or stun a small mule", and has quit smoking.
His views on the war in Iraq and his critiques of militant Islam keep him in demand from publishers.
For Hitchens, who believes the war in Iraq is not only a necessary undertaking but also a winnable venture, the stakes could not be higher. He draws a rather gruesome picture of what he imagines will result from sectarian insurgents gaining control of the Middle East's keystone.
"The grandchildren [of today's insurgents] in Iraq will be able to afford a bandana, a semi-automatic weapon to guard a neighbourhood block - which will be nothing more than potholes, burning tyres, and puddles of rancid water ...
"Where the only cultural activities are going [to] the mosque, stoning women, attending the executions of rival Islamic sects - that will be life."
Later, Hitchens walks out towards the streets of Dupont Circle with a bounce in his step. The enemy is clear, the battle has begun.
"Those who advocate jihad, suicide, murder and Sharia law are considered just part of the mosaic of gorgeous diversity.
"Well, they're not - fundamentalists are the negation of diversity. Unless you say that not all positions are equally valuable, how do we condemn them?"