At his height he always seemed in control; you could, said Lyndon Johnson, who once admired him and trotted him out on so many occasions, almost hear the computers clicking away. But when things went sour and Johnson felt McNamara’s doubts, his tongue, always acid for those who failed him, did not spare his prize pupil. He would say to those around him, “I forgot he had only been president of Ford for one week.”

