Five years ago, the 20-year American war in Afghanistan came to an inglorious end. In April 2021, the United States had begun its final withdrawal, with the goal of pulling out the 2,500 U.S. troops that remained in the country by September. Within weeks of the first U.S. departures, the Taliban had swept up scores of positions as Afghan government forces melted away. By early August, the group had taken control of most provincial capitals. Finally, on August 15, 2021, the U.S.-backed government in Kabul collapsed. Hundreds of thousands of terrified Afghans besieged the city’s airport. Roughly 120,000 were evacuated in planeloads by the United States, its allies, and even groups of private citizens. In a heartbreaking final blow, 13 American service members died in a suicide bombing at the airport four days before the last U.S. soldier departed on August 30. Two decades of heroic effort had ended in shame.

Recriminations followed—some justified, some not. The same group that had harbored al-Qaeda while it planned and carried out the 9/11 attacks had triumphantly returned to power, and fears of a resurgent terrorist threat mounted. After all, the main reason that successive American presidents had decided to keep U.S. forces in the country for so long was the belief that without them, Afghanistan would once again become a safe haven for terrorists even if the Taliban did not manage to take full control.

Nothing of the sort occurred. Over the past five years, not a single act of terrorism against the United States was carried out by a group based in Afghanistan. Washington spent roughly $1 trillion on the war. More than 120,000 Afghan civilians were killed or injured. More than 775,000 American service members were deployed to Afghanistan, more than 20,700 were injured, and more than 2,400 died—all to defend against a threat that turned out to have been exaggerated.

If American officials had known then what they know now, many of them—including me—would have argued more strongly for an earlier withdrawal. This is an uncomfortable point of view to adopt. It calls into question the judgment of leaders, the effectiveness of the policy process, and the value of the entire effort. Washington might have seen a better outcome, or at least a shorter war, if officials had more seriously debated withdrawal earlier, considered a wider range of threat assessments, pursued negotiations sooner, and, in some cases, recognized the bias instilled by a distaste for defeat.

Five years on, the greatest danger is not that a terrorist safe haven might once again emerge in Afghanistan. A graver threat comes from the risk of collective forgetting. Today, the longest American war rarely figures in public discourse. Americans occasionally acknowledge the noble sacrifices that thousands of U.S. service members made in the conflict. But the country moved on, eager to forget those final days. The riskiest form of forgetting would be for American leaders to fail to recall how perilous it proved to accept high costs and terrible losses, all in response to the fears of the moment. Remembering that will help them avoid future anguish.

“YOU ARE WORTH PROTECTING”

On October 7, 2001, President George W. Bush invaded Afghanistan in retaliation for the 9/11 attacks that had stunned the world. Within months, a combination of U.S. airpower, special operations forces, intelligence operatives, and the Afghan militia known as the Northern Alliance had chased out al-Qaeda and upended the Taliban regime led by Mullah Omar. A new government was formed under the Afghan leader Hamid Karzai. For the next four years, the country was deceptively peaceful. This initial success helped tempt the Bush administration into invading Iraq in 2003, leading to a brutal war that captured most of Washington’s attention for the next five years. During that time, the Taliban regrouped. By 2006, they were regaining territory and seriously challenging the Afghan government.

Throughout this period, the United States was gripped by a fear of terrorism, its anxiety fed not only by the horrors of 9/11 but also by the anthrax attacks that followed in their wake and a series of lethal jihadist bombings and foiled plots in Europe in the mid-2000s. “The global war on terror” was raging, and Afghanistan was the main theater. Countering terrorism was unquestionably the center of U.S. military activity in the country, a mission articulated by presidents, secretaries of defense and state, military commanders, and intelligence chiefs.

The United States had other ambitions in Afghanistan, as well, including a nation-building mission that aimed to establish a sustainable democracy. Bush declared this goal explicitly, and in spite of his successors’ efforts to back away, it remained an implicit part of the American project. But without the terrorist threat, there would have been no war against the Taliban, no arming and training of the Afghan military, no nation building, and no democracy promotion. Terrorism was always the driving concern.

Washington understood little about the Taliban.

For many of the men and women on the ground, that mission justified their efforts and losses. As Ross Berkoff, a U.S. Army lieutenant stationed in Kandahar in 2003, wrote in his diary: “September 11, 2001, is a day that will live in infamy and the fact that Afghanistan became a new place for U.S. soldiers to deploy is directly tied to that infamous day. . . . I am here to respond. We’re here in response.” In a 2019 memoir, Kyle Carpenter, who fought in Afghanistan as a member of the U.S. Marine Corps and received the Medal of Honor, summed up his feelings about his service on behalf of Americans: “You are worth protecting, you are worth fighting for, you are worth time in a hospital bed and deep scars on my body.”

That is not to say that the strategy was always clearly communicated or convincing. Many U.S. troops on the ground were not directly involved in counterterrorism or special operations missions. For some, engaging in firefights in remote mountains and deserts with local Taliban, being targeted by improvised explosive devices, and trying to build up the troubled Afghan government and army seemed a far cry from fighting dreaded international terrorists. Some developed deep skepticism about the purpose of the war, which could turn to resentment when fellow service members died or were wounded.

From 2009 to 2011, I served as the U.S. State Department’s political officer in Garmser, a rural district in the southern province of Helmand. I was part of a small team of around half a dozen civilians attached to a U.S. Marine battalion, advising the district governor, the police, and local tribal and religious leaders. Just about every Afghan in the region believed that without U.S. forces backing a strong army and police force, the Taliban would return. A few claimed that al-Qaeda would come with them.

As far as I could tell, there was little to suggest that al-Qaeda was active in Garmser or elsewhere in the south. The........

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