2015 marks the centennial of the Armenian Genocide, a series of organized if not well-orchestrated massacres by Ottoman Turkey of its Armenian minority. Turkish ultra-nationalists continue to deny or minimize the slaughter, but Thomas de Waal of the Carnegie Endowment for International Peace finds more than sufficient evidence for mass murder. His project in writing Great Catastrophe is to get past rancorous and unyielding politics on both sides. He finds that religious and cultural leaders have made steps, but the complications of regional politics and the clamor of entrenched constituencies have frozen progress on the political front. Trauma and paranoia mar the psychology of negotiation in a pathology of animosity and distrust that has proven hard to cure.