Pope calls WWI a warning "we never learn'

Pope Francis says World War I should serve as a severe warning to reject a "culture of war."

But Francis observed that the war's lessons have been ignored, saying "it seems we never learn" as he addressed faithful in Vatican City's St. Peter's Square on Sunday.

The pope, who often decries the arms industry, added: "Let's invest in peace, not war!" Francis noted that the bells of St. Peter's Basilica and of churches worldwide would toll Sunday to mark the 100th anniversary of the war's end.

He called the 1914-18 war "a severe admonition for everyone to reject the culture of war and search for every legitimate means to end the conflicts still bloodying several regions of the world."

Francis also quoted the definition of war as "useless slaughter" provided by Benedict XV, who was pope during World War I.