In South East London yesterday, when Ingrid Loyau-Kennett approached Michael Adebolajo who in his blood-drenched hands held a knife and a meat cleaver after having just murdered a British soldier, she displayed exceptional courage. But she also showed there is an alternative to trying to crush violence with greater violence: diffuse the violence by creating a space within which anger can be translated into words.

Behind most acts of political violence there are statements that the perpetrators imagine can be heard by no other means. Sometimes, all that de-escalation requires is simply to listen to whatever they have to say.

Politicians and some security experts often argue that to listen to terrorists is to capitulate to terrorism — that it is akin to being manipulated by a child’s tantrum and will “reward” terrorism.

The opposite — that refusing to listen, merely closes off alternatives to violence — can just as persuasively argued.

Indeed counter-terrorism seems as much as anything to be driven by its own counterproductive emotional logic. Terrorism emasculates the powers of the state. It makes those who struggle to prevent such violence appear impotent and thus provokes what in some ways are ritualistic displays of counter-violence.

In these displays, paradoxically, the power of the enemy has to be simultaneously inflated and thwarted. Events that are in many ways isolated and involve tiny numbers of people, get woven together into a global phenomenon: the multi-headed hydra of terrorism.

A small bomb goes off in Boston or a man is brutally cut down in London, and governments respond as though the first shot had been fired in the run up to an invasion. The more the threat is inflated, the easier it becomes to justify what objectively often constitutes a massive over-reaction.

Terrorism is political and psychological and requires a political and psychological response — a response that reflects a realistic assessment of the actual magnitude and diverse nature of the threat and a recognition that those who choose to speak with violence generally regard such violence as a means to an end.

Even if their methods have no moral justification, the issues that trigger acts of terrorism will retain the power to inspire further bloodshed for as long as governments insist that security alone must be their preeminent concern.

As Ingrid Loyau-Kennett demonstrated, there are times when it actually requires more courage to listen than it does to fight back.