Youth is kind of the guiding light of "For Esmé – With Love and Squalor" – the war-scarred protagonist is brought back to life by a letter from a young friend of his, whose strength and resilience reminds him that life can go on. However, these noble traits aren't the only things that recommend youth here; Salinger is also really interested in its delightful, whimsical quality. This story occasionally has something of a "kids say the darnedest things!" tone; we, the readers, are asked to see youth as amazing both for its strength and its hilarity, two things that the author captures amazingly well.
The strength, innocence, and resilience of childhood are the only things that can counteract the horrors of war in "For Esmé – With Love and Squalor."
"For Esmé – With Love and Squalor" is at the same time a war story and a joint coming-of-age story, for both Esmé and the narrator.