Armed soldiers in the streets; military aircraft hovering in the skies; recurring words like "war" and "retaliation"; weary, dirt-streaked, rescue workers being applauded through the streets; stories of human beings, still breathing, with 70 per cent burns on their bodies, their hair melted into their skin; sobbing relatives cradling photographs of loved ones already turning sepia in the imagination; grim leaders mouthing risibly hollow words about "taking appropriate security precautions" to protect their citizens - the same citizens who are balking at simple, everyday routines they took for granted like going to the shops, buying a coffee, hopping on a plane.
The reality that has gripped Northern Ireland for over 30 years has come home to the land of the free and the home of the brave. As the vibrant images of the missing and confirmed dead multiply and scorch themselves into our psyches, as details of their final moments seep into our nightmares amid reports of 30,000 body bags being ordered into Manhattan, people shake their heads wonderingly and ask - "how could any human being be capable of such bottomless hatred? What kind of monsters cheer such atrocities?"
They are baffled by the folly of suicide bombers who believe such deeds are a ticket to the highest station in paradise. They feel nauseous at the sight of a woman in Muslim garb celebrating in Palestine. They despair at a Middle East poll which shows 70 per cent of people to be in favour of martyr-bombings. They throw their hands up at the news that a Muslim school in London has closed because of violent threats directed at its children.
And in that state of awe and revulsion at the nature and scale of this week's crimes, it is easy to forget that only a week before, the world had been transfixed by footage of other suffering children, sobbing little Irish girls walking to school through a hate-filled cauldron peopled by creatures of a different religion.
Easy to forget the fathomless hatred that fuelled the murderous assaults on Omagh, Manchester, Enniskillen and the little Quinn boys, or the dancing that once accompanied news of the murder of British soldiers.
Easy to forget the bewilderment of other faiths at the apparent ease by which IRA men could avail themselves of Catholic absolution after committing heinous crimes.
Easy to forget the progress of our home-grown fascist thugs who terrorise their own working-class communities into submission with punishment beatings, shootings and forcible expulsions.
Easy to forget the malevolent reach and continuing appeal of the so-called "Real IRA", preening themselves as the equals of bin Laden's lieutenants, though with one significant distinction - they scurry like rats from the hell they have created rather than immolate themselves.
Easy to forget that less than 24 hours into America's gut-wrenching grief, members of the same band were bidding for glory by attempting to murder three RUC officers with a bomb.
And just as each atrocity in the North brings out the justifiers, with their reminders of "another side to the story", so did they emerge to remind us of another side to the American one: the million Iraqi children dead from US-led sanctions; the third of the Palestinian population of Gaza and the West Bank which survives on £1 a day, cheek by jowl with a US-subsidised, first-world Israel; the Afghans condemned, not only to the barbarous rule of the Taliban (who began life as the well-funded pets of the US), but also to be the victims of other mass-murderous US hunts for Osama bin Laden; the swaggering, ignorant disdain with which a neophyte US president has been trashing international treaties and scorning bodies like the UN - the same bodies from whom he was suddenly seeking unconditional co-operation and "shoulder-to-shoulder" support this week as Air Force One searched American skies for a safe haven and the White House was being evacuated.
Although such reminders are valid and vital to America's survival, it just seemed too early to air them. While shoot-'em-up Hollywood shelved plans to release Schwarzenegger's latest disaster epic (in which a terrorist bombs a Los Angeles skyscraper), Americans were confronting sights, smells, emotions and grievous loss on a scale that no Die Hard movie could have prepared them for.
While New York's mayor gently implied that the search and rescue mission had come down to recovery of body parts, that simple patriotism found outlets of stunning courage and immortal imagery.
The raising of the Stars and Stripes by three dusty firefighters over the twisted ruins and mass tomb that was once the iconic World Trade Centre, stirred echoes of the classic second World War image of US marines after Iwo Jima, and feelings that many hardly knew they had.
And so many calls of love, some of extraordinary heroism, from doomed souls to distraught partners and parents, are surely proof enough that the so-called selfish gene is no more than fiction.
For every Osama bin Laden and power-crazed IRA stooge, there are millions of ordinary human beings on this island and elsewhere, yearning for a meaningful way to reach out to the suffering and the bereaved, for whom as John Montague put it, there will be "no peace after the deluge, no ease after the storm . . ."
What will we learn from this? In the rush to hunt down the guilty, will the voices of sense and vision be lost? Will cynical men and women see only opportunities to further oppress the weak and the marginalised, in the guise of smashing international terrorism?
Will we in Ireland finally acquire the wisdom and courage to yield up our murdering fanatics, stop legitimising them in our assemblies, learn to recognise extremism's inevitable pay-off in the mass graves of Bosnia, Kosovo and the World Trade Centre?
Will our British neighbours finally learn that nuclear power plants are vulnerable to more sinister forces than in-house Homer Simpsons? Will our sorrow and mourning in the end signify nothing more enduring than banks of decaying flowers and a few books of signatures?