MY ten-year-old son looked glum and thoughtful: "Mum, my favourite TV programme, Cardcaptors, isn't on because of this war thing." This was Tuesday. I was listening to the news on the radio. The boys were watching it on television in the next room.

Our eight-year-old appeared. Rather disturbingly, he was smiling excitedly, clearly enjoying the dramatic nature of the footage: "Come quick and see this, people are leaping from the buildings."

"Does this mean there is going to be a nuclear war?" said the eldest. "I'm scared," said the six-year-old. The two-year-old was just thrilled by the sight of familiar vehicles on screen: "Police car. Fire engine," he pointed.

Children look to us to interpret what is happening in the world for them. But when we, as adults, are struggling to make sense of it ourselves, it is difficult to find the words we need to explain and reassure.

My sons watched events unfolding, live, on television with the sense that it was something close to home, for the United States is no longer the distant land it appeared in my childhood.

They know their own parents have been to the top of the World Trade Centre. They have seen the photographs and longed to go too. We had even planned a short family break in New York in the next year or two.

Their uncle, up until six months ago, worked in the Pentagon. We stayed with him in Washington two years ago.

At school, they have American friends, whose parents work at the nearby Menwith Hill US base, on the outskirts of Harrogate. And their father has flown to the US many times on business.

This is a place they can identify with. So, in one sense, it all seems horrifyingly real. But of course, they clearly, like so many adults watching, found it hard to believe this wasn't a film.

They have seen Godzilla stomp these same streets. Didn't James knock King Kong off the summit of the Empire State building after landing his Giant Peach on the spike? And didn't Superman save the world from impending disaster here? They have seen towering infernos, collapsing buildings and huge explosions in the centre of New York before - but none of that was true.

"These are real people, that's somebody's sister, somebody's brother, somebody's mother," I felt I had to explain as they watched office workers jumping from the twin towers, clearly confused as to whether this was a Hollywood movie or reality, whether they should be entertained or horrified.

"They aren't actors. What has happened is terrible and shocking, an incredible act of terrorism, something momentous which could change the course of history," I said. "I wish you had never had to see it, but this is a day you will talk about and read about in your history books in years to come."

It is impossible to shield them from these images, which reveal such a terrifying human capacity for hatred and wickedness. They have discussed it in school and prayed for the dead in assembly.

Like all of us, they are now aware of the fragile nature of the safety we once all took for granted, of living in a world in which mass destruction can happen so easily.

The older boys read the headlines in Wednesday's newspapers for themselves - War, World On The Brink, Apocalypse, Hell on Earth.

This raised yet more questions - questions I wasn't always able to answer.

What's going to happen next? Is there going to be a big war? Will someone attack our country?

I try to reassure them. But I can't lie or make false promises. I am aware that, unlike in a Hollywood movie, American scriptwriters do not control this plotline. We don't know what is going to happen in the months ahead.

Of course, we all hope it will end just like it does on the big screen, that the perpetrators will swiftly be brought to justice and good will prevail. That's the sort of world we want our children to continue growing up believing in.

But such innocent childhood illusions were brutally shaken by Tuesday's events. Life, they are learning fast, doesn't always turn out like it does in the movies.