Pope Francis arrives in Ireland tomorrow for a hectic weekend which promises to be one of the most delicate missions of his papacy. Adherence to the Catholic church there, while still comparatively strong, has plummeted since the last papal visit in 1979. The current pope was invited to Dublin by the World Meeting of Families, an international Catholic festival which a former Irish president, Mary McAleese, has called a “right-wing rally”. He will also hold an open-air mass for 500,000 people and meet homeless people and sex-abuse victims. In Ireland, feeling runs high about the sex crimes and violence perpetrated in churches and church-run institutions, and about the cover-up of these misdeeds by senior clergy. The visit follows a devastating report about abuses over 70 years by more than 300 priests in Pennsylvania, to which the pontiff has responded with a 2,000-word nostra culpa: “We showed no care for the little ones.”