Benedict made the appeal in this small mountain town in Italy's Veneto region while on vacation. He recalled that 90 years ago — on Aug. 1, 1917 — predecessor Pope Benedict XV urged a similar end to the first World War, then ravaging this part of northern Italy.

"While this inhuman conflict raged, the pope had the courage to affirm that it was a 'useless slaughter,'" Benedict said. "These words — 'useless slaughter' — contained a fuller prophetic value that can be applied to so many other conflicts that have cut off countless human lives." ...