Commandos were already some of the most highly trained soldiers in the army, but he was looking for something more profound, and rarer: an ability to think and react independently. Individuality and self-reliance are not always highly prized in an army. Indeed, many officers prefer soldiers to do exactly what they are told, without question or, indeed, thought. But Stirling was insistent that this unit would not be composed of biddable yes-men: “I always hoisted onboard guys who argued.”

