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.
War is bad. If you didn't already know this, just read "For Esmé – With Love and Squalor" to understand just how bad. Despite the fact that we don't see any of the stereotypical elements of a war story here, we see its terrible fallout, in the form of our protagonist, a character who is basically destroyed by his experience of battle. We also see what war does to the innocents that don't even participate in it (for example, children who lose parents in it). In some ways, not seeing the events of the war in this story make it all the more horrifying – instead, Salinger simply hints at it, and asks us to imagine the terror of war ourselves.
In Salinger's short story, the association of war with "squalor" breaks down any notions of the nobility or pride of fighting for one's country.
The removal of any political elements renders war seemingly meaningless, and thus more traumatic, in "For Esmé – With Love and Squalor."
OK, this is the story of a grown man and a thirteen-year-old girl, so you might be alarmed to see "Love" as one of the themes. However, don't flip your wig – this isn't Lolita, and we're certainly not talking about romantic love here. No, instead we're talking about other kinds of love – for example, familial love, friendship, even a hint of bromance. Love, says "For Esmé," comes in all different kinds, and all of it is productive. This is a story of simple human connection, and what a fundamental impact it can have on a life, even in the darkest of times.
The one thing that keeps Esmé going is her abiding love for her father; this love is the source of her strength.
The narrator's own life is possibly devoid of real love, yet he is inspired by Esmé's capacity for it – though she herself is concerned about her coldness, he sees that she truly loves her family, and this ability to love is what makes her so compelling.
Any time you have a writer writing a story about a writer, you just know that literature is going to be a big deal. "For Esmé" is no different. While this story is, on one hand, about a soldier going through a war, it's also about a writer learning how to find his voice. There are several moments in the story where we are reminded that our protagonist is a writer, both by his words and his actions. So, we constantly have to ask ourselves what the events of the story have to do with his ultimate destiny – which is to become the guy writing the story (whew, is that meta or what!).
The ultimate destiny of the narrator/Sergeant X, to become a real writer, could not come to pass without his experience in the war.
One of the "faculties" that Sergeant X loses and regains after the war is the faculty of writing; we see him lose control of his own ability to write in Gaufurt, but, from the story's frame narrative, we know that he ultimately regains it.
"For Esmé" plays upon a common theme of war fiction, the idea of the American soldier abroad. The way people elsewhere (in this case, in England) view Americans is a central theme here. When looking back on World War II, Americans tend to view themselves pretty unilaterally as the good guys, but this story, written by an American author, highlights the fact that, even though US soldiers were fighting on the right side, it doesn't mean that they're all heroes. In fact, the story examines the whole idea of wartime heroics in a questioning light.
The tension between the American soldiers and the English civilians they interact with further destabilizes the myth of wartime heroism.
The narrator's unconventional sympathy for the arrested German woman whose house he and the other soldiers live in demonstrates his understanding of the suffering inflicted on people on both sides of the war.