Sometimes they have to lie. As the British death toll in Afghanistan rises past 400, every news item tells of reverses, mistakes and a desperation to withdraw. Someone has to hold the line. Those whose job is to fight and possibly die for their country need to believe they do so for a purpose. A nation bidding them to die needs it too.

Hence the prime minister has to assert the six-year attempt to cleanse Taliban from Helmand province as "vital to our national security", when everyone knows that this is absurd. The defence secretary, Philip Hammond, has to say: "We owe it to the all too many who have sacrificed their lives to see this mission successfully concluded." The chief of the defence staff, Sir David Richards, has to claim that "truly impressive" progress has been made, and "We will hold our nerve". The former head of the army, Sir Richard Dannatt, asserts that we have "exposed al-Qaida's cynical manipulation of Islam, and so made the UK and the west safer". The general on the ground, James Bucknall, says that "now is not the time to blink".