When it is pointed out that Sri Lanka has, in fact, never experienced an act of violence attributable to Islamists, and that at this rate of conversion it will take the island’s Muslims about 10,000 years to convert the rest of its 21m inhabitants, Mr Gnanasara simply shrugs. His hoard of evidence does not really need to add up. In Sri Lanka, as across most of South Asia, surprisingly large numbers of people among groups that enjoy overwhelming numerical superiority seem eager to convince themselves that their identity is somehow in mortal danger.