(Atria)

Upper-class Englishmen used to send their sons on a grand tour of Europe as an obligatory part of their education. The young men visited cathedrals, museums, castles and temples — the cultural foundations of Western Europe. Their mission was to absorb the values of others, and many of them wrote about it. Much of their writing was informed, urbane and articulate, and it created a particular literary genre. This itself became part of England’s cultural foundations. Literature will do that: Begin as commentary, then evolve into cultural core.

America has developed its own grand tour. Since 2001, we’ve sent more than 2 million young men and women on obligatory tours in the Middle East. Their mission was to impose our values on others, and they, too, have written about it, creating a new genre of war lit. Their backgrounds and experiences vary, as do their voices. These writers are smart, observant, ironic, astute, sober, angry, idealistic, cynical, grieving, scared and passionate. They’re men and women, veterans and civilians, fobbits and grunts: Siobhan Fallon, Katey Schultz, Helen Benedict, David Abrams, Adrian Bonenberger, Ben Fountain, Phil Klay, Elliot Ackerman and, of course, Matt Gallagher. Everyone who reads war lit knows Matt Gallagher.

Gallagher began writing about the war in Iraq from inside it. An Army lieutenant stationed outside Baghdad in 2007, he started a lively, candid and intelligent blog, attracting thousands of readers. But when he reported refusing a promotion so he could stay with his men, the Army felt he’d become too candid. They closed down his blog — although they made him a captain anyway. Gallagher left the Army in 2009 but has continued to write about it.

His first book, “Kaboom: Embracing the Suck in a Savage Little War,” was based on the blog, but his new book, “Youngblood,” is a novel. While his nonfiction was visceral, immediate and reportorial, his fiction transforms direct experience into something more layered and complex.

Author Matt Gallagher in Brooklyn, 2015. (Brad Jamieson)

The narrator of “Youngblood” is Jack Porter, a young Army lieutenant stationed in Ashuriyah, a small town outside Baghdad. The Americans are now about to withdraw from Iraq, and their mission is “Clear, Hold, Build.” But it’s anything but clear. They’re trying to eliminate enemies and support friends, but they’re caught up in tribal hostilities, religious feuds, deceptions and direct attacks. They make regular payments to ensure loyalty from local sheikhs, policemen, Iraqi army soldiers and informers, but loyalty depends on more than money, and everyone knows that the Americans will leave soon. The tribal system is old and complex and uses other currencies besides cash.

Porter struggles with the challenges of the mission and those of his command. He’s worked hard to establish trust, loyalty and respect with his platoon, which he’s named Hotspur. All this is threatened by a newly assigned staff sergeant, Daniel Chambers, who’s been stationed here before. Chambers is tough, cynical and subversive. He reprimands the soldiers, renames the platoon and challenges Porter’s authority.

Everything is challenging in this theater of threat and ambiguity. American errors abound. Civilians are killed by mistake or recklessness, intel is wrong, and Hotspur loses men to enemy attacks. Porter hears about the mysterious Shaba, an American soldier who spoke Arabic, moved among the Iraqis and died under strange circumstances. He hears about a shadowy fanatic called the Cleric. And romantic love enters the story: Porter becomes attracted to Rana, the beautiful married daughter of a local sheikh. In the midst of this, Porter struggles to maintain his integrity, as an officer and as a human being, while he guides Hotspur through its last months of deployment.

Gallagher’s voice is vital, literary and sometimes lyrical. Describing the loading of a rifle, he writes of “the black magic of the gun slamming forward.” An energy drink called Rip It “tasted like liquid crack should, flat fruit punch with a splash of electricity.” He’s generous with humor, one of war lit’s great pleasures. Porter’s mordant wake-up call to his soldiers is: “Yo. The Suck awaits.” He walks into a room full of male fug and asks: “You all sacrifice a yak? Smells terrible in here.”

War is fought on many levels — the abstract and theoretical as well as the personal and immediate — and it encompasses a whole range of responses. Courage, loyalty and determination are part of it; so are rage, hatred and fear. So vivid and complex is this experience that for many veterans it becomes the emotional climax of a lifetime.

Much of the tension in our war lit comes from the collision between the political and the personal, and from the internal struggle for morality. “I want to leave Iraq having done a good thing,” Porter thinks. “A good thing free of qualifiers, of ambiguity. A thing that actually matters.”

Gallagher raises all these issues in smart, fierce and important writing that plays a big part in our new genre. War lit is now part of who we are, holding up a mirror, bearing witness to our culture. As literature will do.

In “Youngblood,” Matt Gallagher shows again how war works in the human heart — something we’ll need to know, as long as there is war.

Roxana Robinson’s most recent novel is “Sparta.”

On Saturday at 6 p.m., Matt Gallagher and Elliot Ackerman, the author of “Green on Blue,” will be at Politics & Prose Bookstore, 5015 Connecticut Ave. NW, Washington, D.C.

Youngblood

By Matt Gallagher

Atria. 340 pp. $26