The world has been horrified by the slaughter in Denver. Horrified, but not shocked.

At least 25 children were gunned down in their school, a disaster that has been greeted with incomprehension.

But we do not feel the same sense of numb disbelief today as we did just three years ago when Thomas Hamilton massacred 16 infants and their teacher at Dunblane Primary School.

It was an act so monstrous, so repellent, that we could never imagine anything worse.

Our shock threshold was irreversibly raised that day.

It is a depressing realisation that we are becoming inured to acts of violence that would have sent us reeling ten years ago. We have not become more callous, the world has become more insane.

The bloodshed at Columbine High School can be added to a growing list of similar, random atrocities.

In Britain, there was Hungerford and Dunblane. In Australia 35 people were shot in Tasmania in 1997; and two months ago ten were injured, one fatally, when a man opened fire in Wollongong.

And only a year ago, the United States was rocked by the actions of two boys who murdered a teacher and four of their school mates in Arkansas.

Unlike Dunblane, the Arkansas massacre and today's tragedy were not the responsibility of a deranged outsider. This was murder of pupils by pupils.

The two boy killers in Denver clearly had a great familiarity with guns.

They picked their targets carefully then killed with chilling efficiency.

Sadly, even carnage on this scale is unlikely to have any effect on America's love affair with firearms.

Such a massacre must be made more probable in a country where children are brought up to love the gun as a symbol of their constitutional freedom.

After the horror of Arkansas, a few brave American politicians talked about reform of the gun laws. But they did not get very far.

Some felt Britain over-reacted to the horror of Dunblane by banning private ownership of nearly all private pistols. Schools, meanwhile, have been turned into fortresses, with secure entries and closed circuit television surveillance.

Both measures restrict freedom.

But in this more violent age, they also greatly reduce the chances of another Denver or Dunblane. Guns are more difficult to buy; schools are harder to enter.

Our society is safer as a result.

If other countries adopted a similar approach, it might prevent scenes such as those in Denver becoming all too familiar.

Converted for the new archive on 30 June 2000. Some images and formatting may have been lost in the conversion.