What effect can a writer have in wartime? As a reporter or ­analyst? Poet, prophet, or ­propagandist? Patriot or ­political gadfly? And what in particular when that writer is also a Catholic? Must he or she be a champion of Catholic teaching; should he or she be an exemplar of faith in his or her writing?In the centenary year of the start of the First World War, there are answers, and more questions, in the way four momentous, attritional years touched three Catholic writers – G.K. Chesterton, Hilaire Belloc and Maurice Baring.All had achieved public recognition by 1914, and during and after the Great War they came to be recognised as spiritual and philosophical beacons to a wide constituency of Catholics (Chesterton joined the other two in the Catholic Church in 1922).