Last week’s events in London raised a recurrent dilemma for journalists, including me. It is a huge story when a terrorist kills four people then is shot down in Palace Yard, Westminster. Yet dare we say how fortunate we are that since 9/11 Muslim terrorists have proved incapable of mounting an attack remotely as lethal as that on the Twin Towers? An intelligence officer told me recently that he worries far more about Russia than about Muslim suicidalists, and this must be the rational assessment.