These words were written by Sir Garnet Wolseley, a former Commander-in-Chief of the British army, for The Soldier's Handbook of 1869. They were recycled in the form of a plaque which hung in the operations room of the London Controlling Section, a secret bureau set up by Churchill during the Second World War which was specifically tasked to plan stratagems to deceive the Germans about Allied operations. Churchill famously remarked that ‘in war-time, truth is so precious, that she should be attended by a bodyguard of lies’.

Sociologists, historians and journalists have categorised warfare as an area of human activity where lies are to be expected. But the morality of using deceit against an enemy has often required exploration and explanation. For Christian theologians, the use of lies and tricks against an enemy has been justified by placing such tactics under the general rubric of ‘just war theory’.