If the poets of the first world war probably enjoy a higher profile now than they have done at any time in the last 100 years, it has not been a smooth passage. When Wilfred Owen was killed in the last week of the fighting he was still virtually unknown, and even 25 years later in the middle of another war, when the ludicrous Robert Nichols — the man Edmund Gosse had once seen as a new Keats and Shelley combined — brought out his anthology of first world war poetry, there was still room for only four poems by...