If we discount Samuel Butler’s wishful theory that the author of “The Iliad” was actually a woman, then British novelist Pat Barker may well be the first female author whose central subject has been warfare. Perhaps closer to the mark than “subject” would be “obsession.” In a half-dozen novels, Ms. Barker has written profoundly about war, its consequences and the ways that writers, photographers, and ordinary veterans have struggled to understand the shattering experiences of combat.

Having written two novels with contemporary settings — “Border Crossing” (2001) and “Double Vision” (2003) — Ms. Barker returns to World War I in her moving new novel, “Life Class” (Doubleday, 256 pages, $23.95). The Great War was the subject of her masterwork, the “Regeneration” trilogy — “Regeneration” (1990), “The Eye in the Door” (1993), and “The Ghost Road” (1995) — which follows real-life poets Siegfried Sassoon and Wilfred Owen. The writers — and Ms. Barker’s own remarkable creation, the cagey, bitter Billy Prior — meet while recovering from shell-shock at a military hospital.

With “Life Class,” Ms. Barker has turned her attention to painters. Unlike the traumatized veterans of her trilogy, the three artists in her new novel are young, prewar students wary of — in some cases, even unconscious of — the brewing cataclysm. Kit, Paul, and Elinor study at London’s Slade School of Art — when they’re not drinking, arguing about art, falling in and out of love or bicycling through a summer weekend at Elinor’s family’s country home.

Ms. Barker is extremely skillful at conveying the sweet yet squalid nature of premarital sex when Victorian proprieties still held, yet the war made everything desperate. In returning to the period, in fact, Ms. Barker doesn’t seem to be digging old ground. Rather, the war was such a profound cultural upheaval that it continues to offer her new material, four books on. All along, her theme hasn’t been just the artistic representation of the war but also the fissures it tore in sexual roles (gay and straight), the class resentments it stoked, the medical advances it provoked. It’s our very modern world that’s crashing down on these people.

For painters, World War I’s abandonment of gold braid and dashing steeds for gas masks and industrialized slaughter presented a huge pictorial and political dilemma. The work of Christopher Nevinson, for one, was censored by military officials for its portrayal of battlefield corpses. Nevinson was part of a circle of Slade artists who provided the inspiration for “Life Class,” including poet Isaac Rosenberg and painters Paul Nash and Dora Carrington (remembered for her later relationship with Lytton Strachey).

How does one aestheticize trench warfare? In “Life Class,” Elinor wants little to do with the war or with men: Both are distractions from her art, which she sees as a haven, not a protest. In contrast, Kit and Paul discover different possibilities. Kit, already a temperamental rising star, finds the machinery of war suits his futurist style. For Paul, painting and ambulance driving offer escapes from his working-class life. All three, in very different capacities, end up at the First Battle of Ypres. In 1996, “The Ghost Road,” the last of Ms. Barker’s trilogy, won the Man Booker Prize. By then, the Booker had become a ticket to American success for Commonwealth novelists; sizable book sales and Hollywood films followed for prizewinners A. S. Byatt, Kazuo Ishiguro and Michael Ondaatje, among others. But not so much for Ms. Barker, who remains a puzzling counter-example, esteemed at home but remaindered in America.

It’s not as if her novels are dense or narratively tricky. Like her other work, “Life Class” is unashamedly realistic, lean but lyrical. As coolly observant as Ms. Barker is, she’s also compassionate and — for those male readers who require large doses of data with their fiction — she’s deeply knowledgeable about combat, in this case, the gangrenous horrors of the field hospital. By rights, Ms. Barker should have a much more significant presence in American bookstores than she does.

And yet there is something about her choice of subjects that has apparently kept Americans at arm’s length. To be sure, World War I looms larger in the British consciousness than the American. Throughout Britain, memorials to the Great War often tower over the ones for World War II; they frequently feature a tally of heartbreaking losses from every family in town. One suspects that if Ms. Barker wrote about World War II (or the American Civil War), she’d have been enshrined on PBS long ago.

Another factor may have been the timing of her books. In the ’90s, the Clinton administration was skittishly trying to do something about Bosnia and Somalia, while avoiding doing anything prolonged out of fear of Republican opposition and an apathetic public. The culture wars were raging; not shooting wars.

But now Americans have been in a frustrating war for nearly five years. Ms. Barker’s writings have a newfound immediacy, especially in her artists’ and writers’ quandaries over conveying the new nature of combat — an issue that can haunt any evening newscast.

“Life Class” does have weaknesses, notably its minor characters who flit by, underexamined. The lack is acute with Henry Tonks, the art instructor who helped advance postwar plastic surgery. But then, perhaps these characters aren’t underexamined so much as preliminary. Here’s hoping “Life Class” is the start of a new trilogy.

Mr. Weeks is the former book critic for the Dallas Morning News. He has a Web log about books at ArtsJournal.com.