We have only just met – I have barely sat down – when Ivor Perl confesses a profound doubt. “How much has it helped in the 80 years, us talking?” By “us”, he means fellow survivors of the Holocaust who have testified to the horrors they witnessed. He wants to know if all the talks at schools, all the media interviews, have achieved anything. “Can you tell me?” I ask him to answer his own question. “I think: nothing.” He urges me to “look around the world” – at Ukraine, at Sudan, at China’s treatment of the Uyghur Muslims. “So...