Violent animal-rights activists pose Britain's biggest home-grown terrorist threat. Unlike those protesters who press their objections peacefully, they are not interested in compromise or negotiation. Their ability to frighten off suppliers to organisations involved in animal research, including banks, stockbrokers and, this week, construction companies, makes them especially difficult opponents.
The Government is right to consider introducing exceptional measures to counteract the unique threat such activists pose, both to the individuals they menace and to research and public health. As we report (page 1), the deployment of troops on the streets of Oxford to combat the threat they pose is now a possibility. Such a move is not without risks. The Army is unlikely to welcome this new home front. The expense would be huge - Cambridge University's plans for an animal laboratory were abandoned partly because of policing costs. And, above all, the prospect of armed troops patrolling a seat of higher learning would alarm many.
The readiness to deploy the Army in mainland Britain would indicate an unequivocal high-level political commitment to animal-based research.
Classifying violent animal activists as a national threat might damage public support for their activities, which is already slight, and limit their ability to raise money. With the Government at last taking a robust lead, those university authorities that have failed to stick their heads above the parapet might be encouraged to do so.
The one group that would not be impressed by the threat to use troops to protect animal research would be those willing to perpetrate violent acts against it. They are likely to regard the move as proof of their importance, and a new opportunity for publicity. But that is an acceptable risk to take to protect such a vulnerable yet vital national asset.