New biographical tidbits have much less to tell us about the author of The Catcher in the Rye than his own early stories

The first anniversary of JD Salinger's death is marked by new revelations on the legendary recluse. Surfacing letters reveal some wholly unexpected sides to The Catcher in the Rye author, including soft spots for Tim Henman and Burger King; while a new biography by Kenneth Slawenski makes the claim that Salinger was "a man scarred by his traumatic experiences as a GI at the western front of the second world war".

Even without subscribing to too rigid a determinism between biography and fiction, this view hardly comes as a surprise to readers whose familiarity with Salinger's work stretches beyond the carefully confined canon that includes The Catcher in the Rye, Nine Stories and a number of longer Glass novellas. Aside, perhaps, from his best loved short story "For Esmé with Love and Squalor", Salinger's most direct treatment of the second world war and combat trauma is found in those stories written during his time in Europe and published in various American journals.

Salinger's famous purism manifested itself in publishing policies: unhappy with every single of work of fiction published prior to his triumphant debut in the New Yorker with "A Perfect Day for a Bananafish" in 1948, he made sure his juvenilia remain unknown to the millions who joined the ranks of his fans following The Catcher in the Rye. Thus, as a Salinger-obsessed teenager a decade ago, I had to resort to Russian translations (respect for copyright has rarely been the trademark of Russian publishing) in order to gain access to the exciting expurgations. That was before the highly unsatisfactory illegal PDF file (which adopts italics – a crucial Salingerian device for rendering intonation – at whim) including 21 early stories and the late, abstruse "Hapworth 16, 1924", gained wide circulation on the internet.

Among many other things, these early stories afford a better perspective on the literary achievement of The Catcher in the Rye. Ever attentive to tone and cadence of everyday speech, Salinger mimics American slang persistently, yet hardly ever to the same effect as in the fiercely idiosyncratic idiom of Holden Caulfield. Curiously, a character by that name is evoked as missing in action and later as killed in a trilogy of stories dating from 1944-1945 and centred on GI Babe Gladwaller, who is defined by the same acute longing for lost innocence of childhood and intolerance to phoniness that would soon become synonymous with Holden. More central to the narrative is Holden's big brother Vincent, arguably the prototype of Seymour Glass: at 29, he is a talented writer with some radio work under his belt. Most importantly, he is often presented through the admiring eyes of other characters, a device that will become the hallmark of the Glass family saga.

"A Boy in France" is a stark, bruised piece of battlefield realism that sees Babe removing a blood-drenched blanket from a dead German soldier's foxhole. He then lies in it, busily regaining his humanity by reading a letter from his little sister. Letters – their language, handwriting and tactile qualities – are a key motif for Salinger; one gets the feeling he would not have celebrated the advent of the email age.

The finale of the trilogy is called, tellingly, "The Stranger". Paying a visit to Vincent's sweetheart, Babe cuts a traumatised, alienated figure. Incapable of reconciling peaceful everyday life with the untold horror of his recent experience, he struggles to find a language to convey the truth about his friend's final moments. To reinforce Slawenski's argument, the rift between the solitary protagonist and society is not, here, a matter of phoniness and sensitivity, but is rooted in the difference between those who went to the war and those who didn't. "The thing that was really terrible was the way your mind wanted to tell civilians these things …" Babe reflects. "Don't let any civilian leave you, when the story's over, with any comfortable lies."

The few following stories feature Holden, the teenager of The Catcher in the Rye, and are little more than homework for the novel. However, even here, it seems Salinger felt compelled to mention the war. The narrator of the touching, accomplished "A Girl I Knew" (given the title "Wien, Wien" by Salinger, who was so enraged by the alteration made by the editor of Good Housekeeping that he only ever published fiction in the New Yorker thereafter) falls in love with a Jewish girl as a teenager sent to Vienna to learn German. In 1945, he returns to the divided city in the capacity of an intelligence officer to learn of the girl's death in a Nazi extermination camp.

While some of it is certainly heavy of touch in comparison with the mesmeric understatement of Nine Stories, I'm still hopeful for an authorised, annotated edition of Salinger's early fiction. Whatever further sensational finds Salinger's private documents hold, with a writer whose (ironically, inadvertent) penchant for self-mythologising was more than matched by his literary gifts, what really counts is the work. Not all that David Copperfield kind of crap.