That the war went on so long may be tragic, but it is hardly surprising.

As the United States leaves Afghanistan after 20 years of war, there can be little doubt that we lost the war — or to put it more gently, did not attain our objectives. In recent weeks, the Taliban have advanced across the north of the country. Bereft of U.S. support, the Afghan army and police have reportedly lost more than two dozen districts over the course of a month and are now fighting on the outskirts of key cities such as Kandahar and Mazar-e-Sharif. Senior U.S. officials have warned of a civil war, while intelligence reports are said to forecast the fall of the Afghan government — which the United States has worked to strengthen for two decades — within a year.

Why did we lose? I’ve been trying to answer that question for 12 years, starting in 2009 when I was a civilian officer in the far-off district of Garmser in Helmand Province. I continued to ponder the question in 2013 and 2014, when I served as political adviser to Gen. Joseph Dunford, commander of all U.S. forces in Afghanistan, and later as Dunford’s senior adviser when he was chairman of the Joint Chiefs of Staff. As I traveled the country with senior U.S. military commanders, I saw that in battle after battle, numerically superior and better-supplied soldiers and police were being defeated by poorly resourced and unexceptionally led Taliban — a dynamic certain to eventually doom the Afghan government unless the United States were to stay indefinitely.

I have found no single answer to why we lost the war. While various explanations address different parts of the puzzle, the one I want to highlight here can perhaps be seen most clearly in the conversations I’ve had with the Taliban themselves, often in their native Pashto. “The Taliban fight for belief, for janat (heaven) and ghazi (killing infidels). … The army and police fight for money,” a Taliban religious scholar from Kandahar told me in 2019. “The Taliban are willing to lose their head to fight. … How can the army and police compete?” 

The Taliban had an advantage in inspiring Afghans to fight. Their call to fight foreign occupiers, steeped in references to Islamic teachings, resonated with Afghan identity. For Afghans, jihad — more accurately understood as “resistance” or “struggle” than the caricatured meaning it has acquired in the United States — has historically been a means of defense against oppression by outsiders, part of their endurance against invader after invader. Even though Islam preaches unity, justice and peace, the Taliban were able to tie themselves to religion and to Afghan identity in a way that a government allied with non-Muslim foreign occupiers could not match.

The very presence of Americans in Afghanistan trod on a sense of Afghan identity that incorporated national pride, a long history of fighting outsiders and a religious commitment to defend the homeland. It prodded men and women to defend their honor, their religion and their home. It dared young men to fight. It sapped the will of Afghan soldiers and police. The Taliban’s ability to link their cause to the very meaning of being Afghan was a crucial factor in America’s defeat.

This explanation has been underappreciated by American leaders and experts, myself included. We believed things were possible in Afghanistan — defeat of the Taliban or enabling the Afghan government to stand on its own — that probably were not. That doesn’t necessarily mean that we should have abandoned Afghanistan long ago, given what we knew at the time. It does mean that the strategy could have been better managed to avoid expending resources on objectives that were unlikely to be attained. Less money could have been spent. Fewer lives could have been lost. But that America couldn’t have done much more than muddle along for years in the face of a relentless enemy is the unsatisfying, sometimes frustrating coda to our longest war.

In 2009, I went to Garmser to serve on a district support team, working alongside a Marine infantry battalion. President Barack Obama’s surge was underway and we were trying to drive the Taliban out of most of Helmand Province. I was hopeful, but also interested to understand why violence had returned after the initial calm that had followed the 2001 U.S. invasion. My instinct based on earlier studies of Afghanistan, including Sarah Chayes’ classic The Punishment of Virtue, was that a main driver of the violence would be grievances — locals driven to fight by mistreatment at the hands of the government or its warlord allies. Indeed, I found ample evidence of grievances — land issues, oppressive policemen and government exploitation of the poppy trade.

Pakistan was also a tremendously important factor for Garmser. The country was already notorious in U.S. government circles for its unwillingness to cooperate against the Taliban, and indeed hundreds of fighters had come from Pakistan to attack the district. Another reason for violence was infighting within the government, its military forces, and its tribal and warlord allies, who failed to unite against the common Taliban threat.

After I left Garmser, I got the chance to view the country from a wider vista as adviser to Dunford. I felt something more was going on. Grievances, Pakistan and infighting could not explain every incident of battlefield defeat. The surge was now over and it was time for the Afghan government to stand on its own so that we could depart. But too often, police and soldiers were giving up in battle. The average soldier and policeman simply did not want to fight as much as his Taliban counterpart. As a result, the government was losing ground on the edges of what we had regained in the surge. At the time, the losses were a trickle. But we knew if they continued, the government would be unable to control key cities and would be in danger of falling. That trickle of losses would eventually become the flood we are witnessing today.

Corruption was part of the problem. As is well-known, the effectiveness of soldiers and police suffered because government officials or military commanders pocketed their pay, hoarded their ammunition and diluted rosters with ghost soldiers. Yet even after accounting for corruption, the police and army were usually still numerically superior to and better equipped than the Taliban in any given battle.

A stronger explanation was that the police and soldiers did not want to put their lives on the line for a government that was corrupt and prone to neglect them. Still, I knew a number of Afghan commanders who took great pains to care for their men. Could we really rest blame on corrupt, uncaring government leaders when Taliban were fighting for less pay, with fewer heavy weapons, far worse medical care, and leaders that for years hid out in Pakistan while their soldiers fought? Moreover, the Afghan special forces — which far and away have better leaders than the Taliban and are exquisitely supported — still had great difficulty fighting without U.S. air support and advisers.

The question nagged me as I left Afghanistan in August 2014. All of these factors were clearly important, but their sum amounted to something less than the hardship that was playing out before my eyes.

A few months after returning home, I attended a discussion at the State Department with Michael McKinley, the U.S. ambassador to Afghanistan. We were having a lively debate about why the Taliban fight when the ambassador interjected. “Maybe I have read too much Hannah Arendt,” he said, referring to the 20th-century philosopher who argued that human action was spurred by fears and past experiences, “but I do not think this is about money or jobs. The Taliban are fighting for something larger.” McKinley captured what I was feeling but had not articulated, and what the Taliban scholar would reiterate for me five years later.

The Taliban exemplified something that inspired, something that made them powerful in battle, something tied to what it meant to be Afghan. They cast themselves as representatives of Islam and called for resistance to foreign occupation. Together, these two ideas formed a potent mix for ordinary Afghans, who tend to be devout Muslims but not extremists. Aligned with foreign occupiers, the government mustered no similar inspiration. It could not get its supporters, even if they outnumbered the Taliban, to go to the same lengths. Given its association with the Americans, the government’s claim to Islam was fraught, even while the Taliban were able to co-opt Afghans’ religiosity in service of their extremist vision. However wrongly, the Taliban could use U.S. occupation to differentiate themselves from the government as truer representatives of Islam. More Afghans were willing to serve on behalf of the government than the Taliban. But more Afghans were willing to kill and be killed for the Taliban. That edge made a difference on the battlefield.

The explanation is powerful, but also dangerous. It can be twisted to mean that all Muslims are bent on war or are fanatics. Such an interpretation would be wrong: Islam is a source of unity and inspiration, not of terrorism or atrocity. To say that a people have sympathy for their countrymen and co-religionists over foreigners is hardly to label Islam as evil. The point is that it is tougher to risk life for country when fighting alongside what some call occupiers, especially when they do not share your faith.

The explanation came up in a variety of conversations and correspondence I have had over the years with Afghans, military commanders, tribal leaders and Taliban themselves. Kandahar’s notorious police chief, the late Abdul Razziq, was renowned for caring for his officers and something of an authority on fighting the Taliban. He told me, “Taliban morale is better than government morale. Taliban morale is very high. Look at their suicide bombers. The Taliban motivate people to do incredible things.”

A Taliban religious leader from Paktia made a similar point:

I hear every day of an incident where police or army soldiers are killed. … I do not know if they are committed to fighting the Taliban or not. Many of the police and soldiers are there only for dollars. They are paid good salaries but they do not have the motivation to defend the government. … Taliban are committed to the cause of jihad. This is the biggest victory for them.

More convincingly, multiple surveys of Taliban opinion by Graeme Smith, Ashley Jackson, Theo Farrell, Antonio Giustozzi and others have confirmed that the Taliban fight in part because they believe it their Islamic duty to resist occupation and are convinced their cause will enable them to win. Jackson’s survey of 50 Taliban, published in 2019, discovered that they described their decision to join the movement “in terms of religious devotion and jihad—a sense of personal and public duty. In their view, jihad against foreign occupation was a religious obligation, undertaken to defend their values.” Jihad was about identity, she concluded.

This thinking extends to ordinary Afghans as well, many of whom do not subscribe to the Taliban’s extremist political vision but are sympathetic to their invocation of Islamic principles against foreign occupiers. The 2012 Asia Foundation survey, the most respected survey of the Afghan people, found that of those Afghans who strongly sympathized with the Taliban, 77 percent said they did so because the Taliban were Afghans, Muslims, and waging jihad.

Over time, aware of the government’s vulnerable position, Afghan leaders turned to an outside source to galvanize the population: Pakistan. Razziq, President Hamid Karzai and later President Ashraf Ghani used Pakistan as an outside threat to unite Afghans behind them. They refused to characterize the Taliban as anything but a creation of Islamabad. Razziq relentlessly claimed to be fighting a foreign Pakistani invasion. Yet Pakistan could never fully out-inspire occupation. A popular tale related to me in 2018 by an Afghan government official illuminates the reality:

An Afghan army officer and a Taliban commander were insulting each other over their radios while shooting back and forth. The Taliban commander taunted: “You are puppets of America!” The army officer shouted back: “You are the puppets of Pakistan!” The Taliban commander replied: “The Americans are infidels. The Pakistanis are Muslims.” The Afghan officer had no response.

Or in the shorter Afghan proverb form: “Over an infidel, be happy with a weak Muslim.” 

The literature to date has respectfully neglected this explanation — in a country where people have eagerly tried to convert me to Islam, where religion defines daily life, and where insults to Islam instigate riots. The largest popular upheaval I witnessed firsthand in Afghanistan was not over the government’s mistreatment of the people or Pakistani perfidy. It was hundreds of angry villagers marching miles to the dusty bazaars of Garmser, protesting a rumor that an American had damaged a Koran.

It would be incorrect to say that U.S. commanders on the ground were oblivious to the morale problems of the Afghan army and police. Certain commanders such as Lt. Gen. Karl Eikenberry realized that the Afghan army desperately needed a sense of nationalism that could never be imbued by foreign forces. But that U.S. occupation might be clashing with Afghan identity and giving the Taliban a significant advantage was rarely considered. Most generals and officials looked instead to solutions such as training, improving leadership, addressing grievances and countering corruption.

In fairness, it is possible that significant improvements in these areas might have made a difference. Theoretically, if grievances had been addressed, or if corruption had been thwarted, or if government leadership had cared more for their troops, it might have counteracted some of the morale problems engendered by fighting alongside an outside occupier. Practically, however, none of these problems were themselves easy to overcome. And it would have been even harder to overcome the Taliban’s ability to outfight, outlast and out-believe government forces — the most intractable problem of all.

Will the situation change with U.S. departure? Will the credibility of the Taliban’s war against the government weaken when we are gone, allowing Ghani’s government to stem the tide of their advance? Maybe, but I am skeptical. Twenty years of foreign support has tarred the government in Kabul. It is all too easy for the Taliban to paint it as a puppet. In the summer of 2014, I was eating dinner, cross-legged in a garden, with two old friends — one a tribal leader, the other a security official — in Lashkar Gah, a town that is today surrounded by Taliban forces. We were talking about the pending departure of U.S. troops, which was then the plan, and I mentioned the dangers of Afghans appearing too frequently alongside Americans. They rolled up their sleeves, pointed to their arms, and said: “The paint is already all over us. There is nothing we can do.”

Now, with the Taliban overrunning districts in the north, they will likely press their attack, further emboldened by U.S. departure over the next few weeks. Afghan soldiers and police will suffer from the same morale problems that have plagued them for two decades. Provincial capitals and Kandahar or Mazar-e-Sharif are likely to fall, possibly within a year. After that, Kabul itself will be in danger. The capital may hold, at least for a while, but the government and its allies will struggle to survive, with little chance of regaining what has been lost.

The explanation of how religion, resistance to occupation and Afghan identity intertwined to the advantage of the Taliban and disadvantage of the government helps us make sense of America’s 20-year war. This is not the singular explanation for the outcome of the Afghan war. But it is a necessary one. Its impact is resounding: Any Afghan government, however good and however democratic, could be imperiled as long as it was aligned with the United States. The Taliban were consistently inspired to fight harder and to go to greater lengths than the Afghan army and police. In turn, the United States had to stay longer and longer: civil war in perpetual motion. If any U.S. leader wanted to leave Afghanistan, they had to confront the prospect that the Afghan government was likely to fail, a humiliating future. 

What should the United States have done? From today’s viewpoint, it’s tempting to say we should have left years ago. I don’t think that answer accounts for the dilemmas facing the United States — or, indeed, for human fallibility. The idea that we should have simply pulled stakes presumes that we could have recognized the impossibility of winning in Afghanistan much sooner than we did. Moreover, it unrealistically dismisses the terrorist threat that persisted all the way up to the defeat of the Islamic State in 2016 and 2017 and the domestic political risks of ignoring that threat.

A more realistic view might be that the Afghan war was always likely to drift toward something to be endured over the long haul, an unhappy chapter of American history with few opportunities to change course. America could not easily win and America could not easily get out. The fact we stayed so long may be tragic, but it is hardly surprising.

What we could have done is managed our strategy better. For too long, we set expectations that were too high given the difficulties of understanding Afghanistan and the obstacles we were confronting. Worse, we expended resources, especially in the 2009–2011 surge, attempting to attain massive goals within a few years. A thrifty, humble strategy that could be sustained over decades would have been better than heavy investment seeking wholesale change in a short amount of time. Such a strategy would have muddled through, deploying as few forces as possible, aware that trying to force decisive change would be a waste of resources. Obama basically arrived at this strategy by the end of 2015, having forced down U.S. troop levels from nearly 100,000 in 2011 to around 10,000. I think we could have gotten there much sooner. The end result may well have been the same: The terrorist threat would have receded, President Joe Biden would today be pulling out troops, and the Afghan government would be on the ropes. But in the meantime we would have spent less money and lost fewer lives. That would have been a better outcome, if far from a rousing victory.

For the United States, Afghanistan was a long war but also an experience. It feels wrong to cast the entire experience as bad or evil. Better, I think, to see the good as well as the bad. I would not want to forget the friendships Americans forged with thousands of Afghans who were genuinely trying to improve their country, whether a hard-working farmer, an idealistic technocrat, a heroic commando, an overburdened policeman or a pathbreaking young woman. And I certainly would not want to forget the kindness U.S. servicemen and women brought to many Afghan lives and their dedication to protecting Americans at home. For me, America’s Afghanistan experience is a dark, cloudy front with points of sunlight. The last thing I want to do is condemn it and all those involved.