'Soft power' is an oft-used term and commands an instinctive understanding among journalists and casual observers, who mostly interpret it as 'diplomatic' or somehow 'persuasive'. 'Hard power' is seen, by contrast, as something more tangible and usually military. But this is a superficial appreciation of a more subtle concept - and one key to Britain's future on the international stage. Britain's Persuaders is a deep exploration of this...