David Cameron gave a speech about Islamism and British values at a conference in Munich. Back home, the rows have not stopped since. Much of the fuss has a distinctly synthetic tang. Absurdly, Sadiq Khan, the Labour shadow justice secretary, accused the prime minister of “writing propaganda” for a far-right group that held a rally on the same day. Conservatives chortled that Mr Cameron had hailed the end of multiculturalism. What he actually said was that a doctrine of “state multiculturalism” had encouraged Britons to live segregated lives. In its stead, he proposed a “muscular liberalism” that confronts extremism and promotes a British identity open to all.