In January 1972, when I was a 13-year-old boy in Dublin, my father came home from work and told us to prepare for civil war. He was not a bloodthirsty zealot, nor was he given to hysterical outbursts. He was calm and rueful, but also grimly certain: Civil war was coming to Ireland, whether we wanted it or not. He and my brother, who was 16, and I, when I got older, would all be up in Northern Ireland with guns, fighting for the Catholics against the Protestants.
What made him so sure of our fate was that the British army’s parachute regiment had opened fire on the streets of Derry, after an illegal but essentially peaceful civil-rights march. Troops killed 13 unarmed people, mortally wounded another, and shot more than a dozen others. Intercommunal violence had been gradually escalating, but this seemed to be a tipping point. There were just two sides now, and we all would have to pick one. It was them or us.