It is a question that has become deeper and more problematic with the growth not only of international terror but of immediate mass communication.
At a conference called Every Childhood Matters organised by 4 Children (formerly Kids' Clubs Network) last week, Trevor Phillips, chairman of the Commission for Racial Equality, spoke of the attack in Beslan and remembered his own response as a schoolboy to the tragedy of Aberfan in 1966, when a primary school disappeared under a slagheap.
One hundred and forty-four people died, including a large proportion of the village's children. It was a powerful, highly-charged marker in the lives of the generation now running the country.
Mr Phillips, 50, says he remembers exactly where he was when he learned of the disaster as a 12-year-old and the impact of the black-and-white photo on the front of the Daily Express remains fresh in his mind.
"It was the first time I thought 'children can die'," he said.
Youngsters in the 21st century are exposed to an ongoing stream of real-time moving images of childhood suffering. Aberfan, although caused by human neglect (the Coal Board was implicated in the report which followed) was an accident.
There is a significant difference between the concept that awful things happen to children (as in Aberfan) to the understanding that people do awful things to children (in Sudan, in Beslan). The effect on the children who survived the ordeal in Russia cannot be imagined. But through television, digital cameras and satellite technology, children all over the world watched ordinary people their own age, in the familiar setting of a school gym, who were about to die at the hands of seemingly implacable terrorists. School is meant to be a place where you can trust adults.
Such images have an ongoing impact, and children receive confusing and contradictory messages from the media-saturated world around them.
Increasingly, they are nested in a culture that makes pious noises about protecting children from violence while simultaneously glorifying it. For instance, an advert for a new computer game has appeared on London Underground stations.
Called Viet Cong: Purple Haze, it is promoted with this quote from a review: "Napalm never smelt this good" - a knowing twist on Colonel Kilgore's iconic remark from the bitter anti-Vietnam war film, Apocalypse Now: "I love the smell of Napalm in the morning".
The PlayStation game, rated 15-plus, does not appear to be ironic in its intent. "Experience the danger, fear and unpredictability of jungle warfare,", says its website.
The thought of Napalm, for Trevor Phillips's generation and indeed for most people, invokes another Vietnam war icon - the image of a naked child, burned by this chemical weapon, running from terror.
At a time when visions of terrified children are haunting everyone's thoughts, teachers remain in the front line, helping children to make sense of these contradictions, and to deal with the distressing images in their minds.
What are you telling the children in your class? Please write to Primary@tes.co.uk