In threatening to strike against primary school pupils they are using the same bullying tactics they claim to condemn in children. The disruption provoked at Manton junior school now threatens the survival of the school itself and with it the jobs of its staff.
There is a set of fair procedures in exclusion cases which allows all parties to have their say and have rights of appeal: most teachers, parents and local education authorities accept the present system. With nine million pupils in 25,000 schools it is not surprising that some cases are hard to resolve and that the parties cannot agree on an outcome.
Any fair system is bound to produce some such results. In these cases the proper thing for the teachers to do is to accept that they have not got the decision they wanted but to go along with it. That is the reasonable, democratic, professional and moral thing to do. If the pupil offends again, he or she can be excluded again.
No thoughtful teachers want to be judge and jury, prosecuting and defence counsel, in their own case. The NASUWT wants to adopt the policy of a selfish child: if they don't get their way, they won't play.
The NASUWT is trying to maintain the myth that teachers are employed to teach biddable children only. This has never been the case, although many people like to think there was such a golden age and want to haul it back. No wonder.
The relaxation in parental discipline, children's behaviour ten times worse than it used to be, parents not ashamed to admit that children of seven or eight years old are entirely beyond their control, 13 year-olds knowing more about sex perversions than people of 30, police powerless to deal with a rising tide of violence among city youths . . . this sort of thing is said every day.
A surprise, then, to learn that every word of the previous sentence is taken from 19th-century news cuttings. You can dip into history at any point and find the same moans about the young and the same dreams of a time of innocence, now lost. A union representing a learned profession ought to have more sense of history.
Professionals have to take their clients as they are, and not as they would wish them to be. Some dentists despair of the sweet-rotted teeth of some children, some doctors regard lung-cancer as self-inflicted, some police think speeding drivers waste their resources, some lawyers are repelled by some of their clients - but we all expect professionals to do their jobs and would be appalled if they refused.
We are right to expect professional workers to have a high level of commitment to their work and to face up to the challenge that dealing with imperfect humans brings.
The NASUWT has a history of disgraceful policies. For years it campaigned for women teachers to be paid less than men. When that became untenable it sought higher pay for "career teachers": these were defined as teachers with unbroken service, a nasty way of punishing pregnancy.
The union's approach to discipline is consistent with this authoritarian, taproom masculinity. Strikes against primary school pupils bring shame on the profession. No other teachers' union turns tragedies into publicity stunts in this way and it is time the membership did something about it.
Mick McManus is principal lecturer in teacher education at Leeds Metropolitan University