Siegfried Sassoon, WWI veteran and poet with his lover - aristocratic socialite and Bright Young Thing Stephen Tennant.
  "…Small-scale, essentially confined to a tiny quarter of the metropolis, the Bright Young People, like the Modern Girl and the Modern Girl’s Brother, wielded an influence on the popular conception of ‘youth’ out of all proportion to their numbers. Coming only a few years after a devastating war that obliterated hundreds of thousands of young men the antagonism between youth and seniority that characterized the 1920s was of far greater significance than previous intergenerational disturbance. For all the enthusiasm for ‘youth,’ the talk of ‘new blood’ and the need to sweep away prewar stuffiness, the twenties, practically every commentator of the period agrees, was a difficult time to be a young man. Part of this difficulty lay in the simple fact of his existence. Orwell, a decade later, noted the tremendous feeling of guilt experienced by the young man born in the years after 1900 who, consequently, had managed to avoid military service. ‘The very fact of his being alive was against him,’ Balfour declared, ‘for he was thus prevented from standing level with ‘the boys who had died.” Whatever feats he accomplished, he would always be compared, and nearly always unfavorably, with the war generation lost in the Flanders mud.           But there was more to these anxieties than a sense of generational inferiority. To a failure to emulate the achievements of those killed in the war could be added the insecurities of the new postwar landscape, where jobs were scarce and whole areas of employment seemed set aside for the jealous middle-aged. On the one hand the peculiarly charged atmosphere of the 1920s, with its promise of good times and limitless horizons, had raised expectations among the young; on the other the reality of its economic pressures had simultaneously let them down. Cyril Connolly noted the reluctance of his contemporaries to accept the routine compromises that had done for their fathers: ‘They could not settle down to boring jobs and unprofitable careers with prewar patience and their cleverness seemed a liability rather than an asset.’…”
-D.J. Taylor, Bright Young People: The Lost Generation of London’s Jazz Age.
Not a book directly related to the wars, but highly recommended reading all the same.

Siegfried Sassoon, WWI veteran and poet with his lover - aristocratic socialite and Bright Young Thing Stephen Tennant.

  "…Small-scale, essentially confined to a tiny quarter of the metropolis, the Bright Young People, like the Modern Girl and the Modern Girl’s Brother, wielded an influence on the popular conception of ‘youth’ out of all proportion to their numbers. Coming only a few years after a devastating war that obliterated hundreds of thousands of young men the antagonism between youth and seniority that characterized the 1920s was of far greater significance than previous intergenerational disturbance. For all the enthusiasm for ‘youth,’ the talk of ‘new blood’ and the need to sweep away prewar stuffiness, the twenties, practically every commentator of the period agrees, was a difficult time to be a young man. Part of this difficulty lay in the simple fact of his existence. Orwell, a decade later, noted the tremendous feeling of guilt experienced by the young man born in the years after 1900 who, consequently, had managed to avoid military service. ‘The very fact of his being alive was against him,’ Balfour declared, ‘for he was thus prevented from standing level with ‘the boys who had died.” Whatever feats he accomplished, he would always be compared, and nearly always unfavorably, with the war generation lost in the Flanders mud.

           But there was more to these anxieties than a sense of generational inferiority. To a failure to emulate the achievements of those killed in the war could be added the insecurities of the new postwar landscape, where jobs were scarce and whole areas of employment seemed set aside for the jealous middle-aged. On the one hand the peculiarly charged atmosphere of the 1920s, with its promise of good times and limitless horizons, had raised expectations among the young; on the other the reality of its economic pressures had simultaneously let them down. Cyril Connolly noted the reluctance of his contemporaries to accept the routine compromises that had done for their fathers: ‘They could not settle down to boring jobs and unprofitable careers with prewar patience and their cleverness seemed a liability rather than an asset.’…

-D.J. Taylor, Bright Young People: The Lost Generation of London’s Jazz Age.

Not a book directly related to the wars, but highly recommended reading all the same.