"Vera Brittain was very much the daughter of an upper middle class family whose sons were recruited into the officer corps in the British army.
"The officer corps had a social composition that was not a cross-section of the population. And the way in which trench warfare operated was that the officers were at greater risk than the men that they led. If you want to see the heaviest incidence of loss in the First World War, you can look to social elites.
"They're the families whose men – brothers, husbands, fathers, sons – fell in disproportionate numbers, in huge numbers throughout the war. And Vera Brittain's entire male company, her social world was stripped from her because of her social situation, where she was and who she was.
"Now these people were only part of the story.
"Obviously, the majority of casualties were made up of ordinary people who were not a part of Vera Brittain's circle.
"If you want to get a sense of one of the images of the First World War that lasted longest, it is that the brightest and the best were killed; and they were her friends, they were her fiancée, they were her brothers.
"The world that she faced afterwards was desolate, because she felt, as did many others, that what had happened was the apprentices weren't there anymore: the people who would ordinarily have become the great writers, the poets, the politicians, the artists, weren't there. What the war had done was to destroy potential and creativity. So what she caught was an image of the truncation of millions of lives located within a certain social strata which naturally gravitated towards power, given an equality in those societies, and which was decimated.
"It's true in Germany, it's true in France, it's true in Britain, that the higher up you were in the social scale, the greater were your chances of becoming a casualty of war. And that's because of the fact that these people served as officers, and the younger ones were junior officers in the infantry. They're the ones who were killed off like flies."