The convoy rumbled into the Taliban heartland, a white desert littered with stones. Over the loudspeakers at the local mosque, the Afghan police officers ordered everyone to gather: The commander was here.

Dozens assembled in the mud square to listen as Abdul Raziq, one of America’s most important partners in the war against the Taliban, stood before the crowd, gesturing at two prisoners he had brought along to make his point.

The prisoners knelt with their hands bound as Raziq spoke to his men. A pair of his officers raised their rifles and opened fire, sending the prisoners into spasms on the reddening earth. In the silence that followed, Raziq addressed the crowd, three witnesses said.

“You will learn to respect me and reject the Taliban,” Raziq said after the killings, which took place in the winter of 2010, according to the witnesses and relatives of both men. “Because I will come back and do this again and again, and no one is going to stop me.”

For years, American military leaders lionized Raziq as a model partner in Afghanistan, their “if only” ally in the battle against the Taliban: If only everyone fought like Raziq, we might actually win this war, American commanders often said.

He ruled over the crucial battleground of Kandahar during a period when the United States had more troops on the ground than in any other chapter of the war, ultimately rising to lieutenant general thanks to the backing of the United States. American generals cycling through Afghanistan made regular pilgrimages to visit him, praising his courage, his ferocious war fighting and the loyalty he commanded from his men, who were trained, armed and paid by the United States and its allies.

The Americans were by his side until the very end. When he was gunned down by an undercover Taliban assassin in 2018, he was walking next to the top American commander in Afghanistan, Gen. Austin S. Miller, who celebrated him as a “great friend” and “patriot.”

But to countless Afghan civilians under his reign, Raziq was something else entirely: America’s monster.

His battlefield prowess was built on years of torture, extrajudicial killings and the largest-known campaign of forced disappearances during America’s 20-year war in Afghanistan, a New York Times investigation into thousands of cases during his rule found.

The Times obtained hundreds of pages of documents written by the former American-backed government, more than a decade’s worth of hidden ledgers bearing clues to his campaign of abuse. He transformed the police into a fearsome combat force without constraints, and his officers abducted hundreds, if not thousands, of people to be killed or tortured in secret jails, The Times found. Most were never seen again.

The culture of lawlessness and impunity he created flew in the face of endless promises by American presidents, generals and ambassadors to uphold human rights and build a better Afghanistan.

And it helps explain why the United States lost the war.

For nearly two decades, the American public saw only part of the war in Afghanistan. Large parts of the country and its people were off limits to outsiders, impossible to chronicle fully during the fighting. Now that it’s over, the Taliban are no longer planting roadside bombs, and many have swapped their AK-47s for three-ring binders and a stifling bureaucracy.

The Times spent more than a year visiting parts of Afghanistan that were once active battlefields, trying to figure out what really happened during America’s longest war.

We interviewed many hundreds of people who said their fathers, husbands, sons and brothers had disappeared under Raziq, the police chief responsible for security across Kandahar Province, the birthplace of the Taliban. They saw his rule as little more than a brutal campaign against civilians, underwritten by the United States.

His acts not only discredited the American war effort — breeding profound resentment that pushed people to support the Taliban — but embodied it in many ways as well. Across Afghanistan, the United States elevated and empowered warlords, corrupt politicians and outright criminals to prosecute a war of military expediency in which the ends often justified the means.

The Taliban committed countless atrocities of their own against civilians, including suicide attacks, assassinations and kidnappings for ransom.

But it was a mistake to “keep a really bad criminal because he was helpful in fighting worse criminals,” said Gen. John R. Allen, who said he tried to limit cooperation with Raziq when he was overseeing coalition forces in the Afghan war from 2011 to 2013.

While Raziq’s tactics worked in some respects, beating back the Taliban in Kandahar and earning him the admiration of many who opposed them, the strategy came at a clear cost. It stirred such enmity in parts of the population that the Taliban turned his cruelty into a recruiting tool, broadcasting it to attract new fighters. Many Afghans came to revile the American-backed government and everything it represented.

“None of us supported the Taliban, at least not at first,” said Fazul Rahman, whose brother was abducted in front of witnesses during Raziq’s reign. “But when the government collapsed, I ran through the streets, rejoicing.”

Even some who cheered the ruthlessness Raziq wielded against his enemies lamented the broader corruption and criminality he helped enshrine, a key part of why the Afghan government collapsed in 2021. After his death, his commanders expanded their predation further, extorting ordinary people and stealing from their own men’s wages and supplies.

“What they brought under the name of democracy was a system in the hands of a few mafia groups,” said Qari Mohammad Mubarak, who ran a girls’ school in Kandahar and initially supported the government. “The people came to hate democracy.”

Many American commanders, diplomats and their allies in Afghanistan knew at the time they were bankrolling a war that strayed far outside international law.

“Sometimes we asked Raziq about incidents of alleged human rights abuses, and when we got answers we would be like, ‘Whoa, I hope we didn’t implicate ourselves in a war crime just by hearing about it,’” said Henry Ensher, a State Department official who held multiple posts on Afghanistan, including as the top civilian representative in Kandahar in 2010 and 2011, when he worked with Raziq.

“We knew what we were doing, but we didn’t think we had a choice,” Ensher said.

Most American leaders — including more than a dozen interviewed by The Times — said that Raziq had been seen as the only partner capable of beating back the Taliban in the heartland of the insurgency, where a pitched battle for dominance was underway.

“In the moment, we might have succeeded, but so what?” Ensher said. “The entire enterprise was flawed.”

Many Afghans say Raziq used the Americans and their military might to pursue a personal vendetta, taking vengeance against the rivals his tribe had been fighting for decades.

In interviews, many former senior American officials acknowledged that they never grasped that dynamic. It was a defining characteristic over a generation of combat — how little the United States understood about the war it was waging.

The United Nations, human rights groups and news outlets raised serious concerns about Raziq and his forces, but independent investigations were limited, especially with the region so impenetrable during the war.

To determine the extent of the abuses, The Times combed through more than 50,000 handwritten complaints that had been scrawled into the Kandahar governor’s ledgers from 2011 through the end of the war in 2021. In them, we found the rudimentary details of almost 2,200 cases of suspected disappearances.

From there, we went to hundreds of homes across Kandahar and tracked down nearly 1,000 people who said their loved ones had disappeared, been killed or been taken by government security forces.