But before another moral panic sweeps the country and even more security devices are installed in schools it is worth reviewing the evidence. After all, this is not the first time the death of deference has been announced. “Our youth today ... have contempt for authority ... and tyrannise their teachers,” Socrates said - nearly 2,500 years ago.

However, it would be stupidly complacent to conclude “it was ever thus”. It wasn’t. School massacres, such as those in Dunblane and Colorado are a modern phenomenon. Murders like that of London headteacher Philip Lawrence are another frightening development. Nevertheless, there is no research charting a rise in violence in British schools. In the United States, such statistics are collated, but they sometimes contradict the pessimists’ predictions. Last month he Justice Policy Institute reported that, even counting the 15 Littleton killings, violent deaths in American schools dropped by 40 per cent during 1998-99.

That is no cause for rejoicing, but it is a reminder that things do not automatically get worse, year by year. Indeed, the Government is determined that they will not. It is setting up another 580 learning support units (“sin bins”) and displaying its “zero tolerance” credentials.

But it must know that the policy of “condemning a little more, understanding a little less” (to paraphrase John Major) will not provide lasting solutions. We need to do both. Parents convicted of assaulting teachers should be punished more severely, but we should also address the underlying causes of school conflict.

The ultimate goal must be to create a system that enhances children’s self-esteem rather than reduces it. But in the meantime schools should receive more support from social workers trained in anger management and conflict resolution. Such proposals always provoke guffaws, of course, but as this is one tactic that has actually been shown to work it would unwise to laugh too loudly.