Should there be troops on the streets?

In the wake of terrorist outrages such as Monday’s bombing, the British public tends to keep calm and carry on. We saw it in London after the Westminster attack in March; we saw it yesterday on the streets of Manchester – a stirring sight. That calmness in the face of evil is an attitude that has almost always been reflected by those who govern and lead us. Think of Margaret Thatcher’s steely response to the Brighton bombing. It’s the British way.

But it has, until now, also been the British way not to put troops on the streets unless absolutely necessary. It’s a delicate balance: a prime minister has a duty to reinforce the police, and after a terrorist attack it’s also natural that any democracy would be put on the highest form of alert. But you can go too far. When Tony Blair deployed armoured cars and troops to Heathrow Airport in 2003, after the threat of a missile plot, it was seen as a classic example of over-reach, which served to unnerve, rather than reassure.