There is no reason to believe that this would reduce the likelihood of atrocities such as we have just seen, and in fact there is every chance that it would increase it.

That might be seen as a price worth paying. My point is that it should not be seen as a way of preventing such things happening.

The danger is that if our governments are clumsy in the way they respond there is every danger that it won't just be a matter of continuing and escalating mayhem in our cities, but of actually extending the territories where this horrible perversion of Islam is able to operate.