All wars breed heroes, but some come in unexpected form. Wasil Ahmad was one of the unlikeliest. He was only 8 years old when the war in Afghanistan, already a family affair, set him on a path for vengeance.

One morning, about an hour's walk from the family compound where Wasil slept, his father and three uncles stood guard at a newly built police checkpoint. For years, as the Taliban and the Afghan government had traded control of this stretch of southern Afghanistan, Wasil's family seesawed between both sides. Now, with the Americans pulling out, the men in Wasil's family glimpsed new opportunity—and new jobs—as leaders of a U.S.-backed police force. They pledged to fight the Taliban, to defend their valley from the insurgents.

They girded themselves for battle, which came that morning in the summer of 2012, as the Taliban swept down from the hills of the Uruzgan province and attacked the new checkpoint of the Afghan Local Police. Soon, the crack and pop of gunfire rattled through the valley of Nawa Sultan Mohammad, and the fighting spilled into the surrounding fields. The police, commanded by Wasil's uncle Samad, fought the insurgents throughout the afternoon and into the evening, managing to kill ten Taliban fighters before the attackers were subdued. But three of their own had been gunned down, too—including Wasil's father, Hamidullah.

That night, as darkness enveloped the family's three-story mud-brick compound, Wasil's uncles shuffled Hamidullah's bloodied corpse inside. The boy drew close, his cheeks wet with tears. In the low light, he could see the blood that stained his father's clothes. He was a child, yes, but he knew enough of his world to realize, without even asking, who had killed his father. And he knew what it meant for him.

In the weeks that followed, Wasil's anger hardened into a grim and brutal ambition—one that would launch him toward fame and then toward tragedy. “Teach me how to shoot,” Wasil said to his uncle Samad when he had resolved himself to retribution. “I want to kill my father's killer.”

At first, Wasil's family managed to steer the boy away from his quest for revenge. “We convinced him to keep going to school,” Merwais Ahmad, one of Wasil's other uncles, told me. But as he grew, Wasil refused to forget. Like very few things in Afghanistan, the boy's hatred for the Taliban was simple. It was also unwavering—which was another rarity in a part of the country where the Taliban aren't always the enemy.

His family's own complicated relationship with the Taliban went back years, to the days before 9/11, when the group first came to power and Wasil's uncle Samad became an eager climber in the local power structure. It wasn't religious devotion that drove Samad but, rather, expediency. Like many, he wanted what the Taliban could offer. “At that time, I didn't know what was good or what was bad,” Samad told me. “Everybody likes to have vehicles, a little power, to be on the government's side. The Taliban provided us with fuel, with a better life.”

When the Americans arrived, three years before Wasil was born, Samad fought to repel them. He had battled invaders before—fighting the Soviets as a mujahideen warrior in the 1980s. Now, toiling for the Taliban, Samad buried IEDs in roads and under bridges and fashioned explosive vests for suicide attacks. Samad was a Taliban commander when Wasil was born—and as the boy grew, he became entranced with his uncle's stories of courage and valor.

But by the time Wasil was 8, Samad was having doubts. In early 2012, as American and Afghan authorities were working hard to win the loyalties of fighters like him—offering them jobs and other incentives—Samad broke ranks with the Taliban. Along with 13 of his men, he pledged allegiance to the U.S.-backed Afghan government.

Whether or not Wasil could grasp the complexities of shifting allegiances, his family's fortunes were changing. Samad, now a sworn enemy of the Taliban, was promptly appointed to run a unit of the Afghan Local Police, the region's lone security force. He hired Wasil's father, Hamidullah, a farmer and taxi driver, and his two other brothers—along with 30 ex-Taliban fighters and 40 other locals. They set up five fortified checkpoints and began keeping watch.

It was only a matter of time before the Taliban, eager to repay Samad and his men for their defection, roared down from the highland one morning and put a newly fatherless child on a mission for retribution.

In the months that followed, Wasil pleaded to join his uncle's police unit. And by the time he turned 10, his nagging became too much. As Merwais told me, Samad finally relented. “He had to keep him happy. He was saying, ‘Okay, this is a pistol. Just shoot it like this.’ And he started teaching him.”

Thus began the training of a uniquely gifted child soldier.

When Wasil wasn't at school, he and his uncle—sometimes accompanied by other policemen from the unit—would grab guns and hike into the hills. “We started with pistols, and then I gave him an AK-47,” Samad recalled. “He became very good at hitting targets a great distance.”

Samad's men were impressed—the boy was a natural marksman, and as he graduated to more powerful weapons, he seemed surprisingly unaffected by the recoil of the guns. Before long, Wasil was firing rocket-propelled grenade launchers. “That got him excited,” Samad said. “He was shouting, laughing, and having fun.” Then came mortars, shot from a three-legged stand. Wasil asked his mother to stitch him a police uniform, which he proudly wore nearly everywhere. “He was not on a salary, he was not a legal policeman, but he trained with us,” Samad said.

In some ways, Wasil wasn't unusual. In Afghanistan, a stew of factors—the intractable poverty, the primacy of family honor, and the high desertion and casualty rates within fighting forces—conspire to press children into war in large numbers, especially as foreign forces have pulled out. Last year, half the police checkpoints surveyed in Uruzgan were staffed by officers under 18, according to researchers from the organization Child Soldiers International.

Courtesy of family

The Taliban, which have stormed back to power in recent years all over the country, have been using child soldiers in even larger numbers than the government. In the north, in the Kunduz province, where the Taliban briefly captured the capital last year, insurgents used the schools to train children to fight on the front lines—instructing them in making and planting IEDs and detonating suicide vests at checkpoints. “The Taliban's apparent strategy to throw increasing numbers of children into battle is as cynical and cruel as it is unlawful,” said Patricia Gossman, a senior researcher at Human Rights Watch.