Ban Ki Moon the Secretary-General of the United Nations, visited Sri Lanka last week. He knew from his officials that at least 20,000 civilians had been killed by Sri Lankan troops in the offensive against the Tamil Tigers. Mr Ban never mentioned this figure to his Sri Lankan interlocutors. He saw, while travelling by air over a supposed “no-fire” zone, the evidence of a massacre of thousands of Tamil civilians caught between the army and the insurgents. Yet he has still not confirmed the authenticity of photographs taken from the same helicopter setting out that scene of carnage and mass makeshift graves.