Salman Rushdie – still recovering from the attack last year that cost him the sight of one eye – has never been shy of confronting the excesses of British imperialism. Nor, quite rightly, has he been alone in doing so. Critiques of Britain’s imperial ambitions are as old as the empire itself. Think of Edmund Burke’s attack on the East India “nabob” Warren Hastings, or Samuel Johnson’s critique of American slave-drivers. Even Enoch Powell made a Commons speech, in 1959, about the brutalities of the Hola internment camp in Kenya.  This long and noble tradition has recently been reinvented, with considerable commercial success.…