Americans long remembered where they were when they learned about the sinking of the Lusitania in 1915. The shock and horror of that event, in which a German submarine deliberately sank a British ocean liner with nearly 2,000 men, women and children aboard, produced more than moral outrage. It also reshaped Americans’ perception of the world and their role in it, ultimately leading them into the First World War. But neither their outrage at Germany nor their reconfigured view of foreign policy lasted very long. Ten years later, Americans still remembered the Lusitania, but they did not remember why they went to war — or, more specifically, how they felt about the series of events, beginning with the sinking, that ultimately led them to embrace war as their only remaining option. Instead, they came to regret their intervention in that war and to wonder what or, rather, who had gotten them into it.

Americans have undergone a similar experience over the two decades since the terrorist attacks on Sept. 11, 2001. The feelings and perceptions of threat that led them to war in Afghanistan have faded, and all that is left are the consequences of that decision, the costs in lives and money, the inevitably mixed and uncertain results, and the unanswerable question: Was it all worth it?

We live history forward, in the chaos of onrushing events, without a clear guide. But we judge history backward, smugly armed with the knowledge of what did happen and uninterested in what might have happened. This partly explains the oscillation of U.S. foreign policy over the decades between periods of high involvement overseas and periods of withdrawal and retrenchment. In the case of World War I, the recoiling from what came to be regarded as the great error of intervention led to two decades in which Americans so removed themselves from involvement in Europe and East Asia that they unwittingly helped bring about the next great war they would once again be dragged into fighting. One wonders whether this pattern will eventually repeat itself in Afghanistan.

A collective failure today to recall what the world looked like to Americans after 9/11 has certainly clouded our understanding of the consequential decisions taken in those first years. Today, one reads that Americans went to war “almost gleefully”; that in launching the intervention, President George W. Bush was filled with “optimism” based on the belief that “democracy would flourish when given the opportunity”; that “imperial hubris” led Americans to believe “that we could shape the world in our image using our guns and our money.” Today, we read that even as “the twin towers and the Pentagon were still smoldering, there was a sense among America’s warrior and diplomatic class that history was starting anew for the people of Afghanistan and much of the Muslim world.”

This is a myth, or to use the term preferred by The Post’s extensive report on Afghanistan, a “lie.” For better or for worse, it was fear that drove the United States into Afghanistan — fear of another attack by al-Qaeda, which was then firmly ensconced in the Taliban-controlled country; fear of possible attacks by other groups using chemical, biological or even nuclear weapons; fear of other sleeper cells already hiding in the United States. Experts warned that it was just a matter of time before the next big attack. And these fears persisted.

A year after 9/11, a Pew Research Center poll found that the attacks had “left a lasting, perhaps indelible, imprint on life in America as well as on attitudes toward public policy.” More than 6 in 10 Americans worried about a new attack; 4 in 10 expected the terrorists to use chemical or biological weapons; and more than half of Americans believed the perpetrators of the next attack were already living in the United States. Women worried more than men, with the result that women were, suddenly, about as likely as men to favor increased defense spending and military action. By a margin of 48 percent to 29 percent, Americans agreed that increasing the U.S. military presence abroad was a more effective means of combating terrorism than decreasing it. A month before Bush went to Congress for authorization to use force in Iraq, 64 percent of Americans polled favored using military force to remove Saddam Hussein from power.

The decision to go to war in Afghanistan in October 2001 enjoyed almost universal support — authorizations were approved in September 98 to 0 in the Senate and 420 to 1 in the House. But there was no gleeful optimism about the likely outcome. A month into the war, 88 percent of Americans polled approved of the intervention, but only 40 percent thought it very likely that the United States would be able to drive the Taliban from power, and only 28 percent thought it very likely that the United States would capture or kill Osama bin Laden. This pessimism persisted, thanks in part to the continual warnings by experts and many in government that terrorist networks were growing, along with the chances of another attack. In 2006, these experts were still warning that it was “not over yet” and that Americans remained “all too vulnerable to another 9/11-like tragedy at the hands of the jihadists.”

To read Bob Woodward’s almost contemporaneous account of the Bush administration’s reaction to the 9/11 attacks is to read not of hubris but of panic, confusion, fear and guilt. Bush and his advisers were mortified that they had allowed this uniquely horrific attack on American soil, and their focus was on punishing those who had perpetrated it, as well as those who sheltered them. Bush personally wanted vengeance. As Secretary of State Colin Powell thought to himself, according to Woodward, Dan Balz and Jeff Himmelman, the president “wanted to kill somebody.” He wanted to do so for strategic reasons, as a deterrent to others. He wanted to do so partly to buoy the crushed spirits of Americans unaccustomed to being attacked. But he also wanted to avenge the lives that had been lost on his watch.

Bush had no idea what he wanted to do with Afghanistan once that goal had been accomplished. In truth, the Bush administration would have been content with any stable government capable of fending for itself and preventing the return of the Taliban, al-Qaeda and other terrorist groups. Bush was hardly inclined toward “nation-building.” On the contrary, he and national security adviser Condoleezza Rice and other advisers had criticized the Clinton administration for precisely that — “international social work,” as one critic put it — and had come into office intending to pursue a far more restrained foreign policy. Faced with the problem of Afghanistan, however, Bush officials found themselves with only unpalatable choices. On the one hand, historian Fredrik Logevall writes, “they feared that Afghanistan could descend into chaos,” but on the other hand, they “didn’t want to be saddled with the tasks of nation-building.” Defense Secretary Donald H. Rumsfeld, writes historian and former civilian adviser in Afghanistan Carter Malkasian, “wanted to outsource to Afghan partners and be done with the place as soon as possible.” In the end, Bush officials decided they had no choice but to stay for a while and try to establish a government that would allow American troops eventually to depart without fear of a return to the pre-9/11 circumstances.

This led them into efforts that could be described as “nation-building” but that were basically what the U.S. military has always done, or tried to do, when engaged in occupations in Vietnam and in the Balkans in the 20th century, in Cuba and the Philippines decades before that, and even in the South after the Civil War. Building schools and hospitals, trying to reduce corruption and improve local administration — this has been standard operating procedure following nearly all U.S. interventions.

But the idea that Americans sought nothing less than creating a “Western democracy" rather than “what was sustainable or workable in an Afghan context” is simply wrong. The word “democracy” does not once appear in Balz and Woodward’s eight-part series in 2002. Top officials knew that even bringing stability to Afghanistan was going to be a tall order. When someone suggested that at least it would be easier than dealing with the Balkans, with their centuries-old religious and ethnic conflicts, Rice responded, “We’re going to wish this was the Balkans.”

The United States turned toward nation-building in Afghanistan not because officials were confident of success but because it seemed the least bad of the available options. Nor were these efforts slipped past an American public kept in the dark. One year into the war, 56 percent of Americans favored “coming to the aid of Afghanistan to help it recover from the war,” and fully two-thirds agreed that the United States would have to continue to “deploy troops there to maintain civil order” for the foreseeable future. And still Americans remained doubtful and apprehensive. A year into the war, only 15 percent regarded it as successful; 12 percent called it a failure. And 70 percent thought it was too early to tell. Only a third of the public believed that terrorists were less able to launch a new attack than they had been a year earlier.

Bush was hardly the sunny cheerleader. From the beginning, he worried that Americans were not prepared for the long and difficult struggle ahead. “Our response involves far more than instant retaliation and isolated strikes,” he told Congress in the days after Sept. 11. “Americans should not expect one battle but a lengthy campaign unlike any other we have ever seen.” Certainly, in those first few years after 9/11, that was indeed what Americans expected — a long, nasty conflict with many casualties on both sides. But they regarded it as necessary. Bush never considered simply declaring victory and bringing the troops home. He has said that an option of “attack, destroy the Taliban, destroy al-Qaeda as best we could, and leave” was never appealing because “that would have created a vacuum [in] which … radicalism could become even stronger.” His successors all faced the same dilemma. As Malkasian observed last year, “Every U.S. president since 2001 … sought to reach a point in Afghanistan when the violence would be sufficiently low or the Afghan government strong enough to allow U.S. military forces to withdraw without significantly increasing the risk of a resurgent terrorist threat.”

That is one reason the intervention lasted so long. Another reason was that it was not all one steady downward spiral to failure. There were periods when the situation looked to be more or less under control. After the rapid rout of the Taliban in the fall of 2001, Afghanistan became deceptively peaceful for roughly four years. Bush was able to keep between 10,000 and 20,000 troops in the country, and U.S. casualties in these years were relatively low. On the political front, there was progress to point to: In January 2004, Afghan leaders approved a new constitution, which led to reasonably fair presidential and parliamentary elections and the election of the moderate Hamid Karzai as president. Afghanistan was still far from a “success,” but the progress was enough that the Bush team kept at it, especially given what the administration regarded as the likely consequences of withdrawal. As one Marine and intelligence officer who served five tours of duty in Iraq and Afghanistan recently put it, “At any given point in our 20-year Afghan odyssey, we were always — in our minds, at least — only a year or two out from a drawdown followed by an eventual withdrawal.”

But progress could never be sustained. The rise of a Taliban insurgency in the last years of the Bush administration led President Barack Obama to accept his military advisers’ recommendation for a “surge” of forces in 2009. There followed another period of relative progress. Over the next three years, the surge stabilized important parts of the country, breathed new life into the Afghan army and police, and strengthened support for the government. The costs to the United States went up, however. It was during the Obama surge that American casualties were at their highest — 1,500 troops killed and 15,000 wounded between 2009 and 2012, more than in any other period of the 20-year war. The killing of bin Laden in May 2011 led most Americans to believe that the mission had been accomplished, and Obama started speaking about the need to “focus on nation building here at home.” But as Obama withdrew the troops sent in for the surge and planned further drawdowns, the Taliban recovered, and outside Afghanistan the general terrorist threat increased with the rise of the Islamic State in Iraq and Syria.

Much has been made of the supposed deception that successive administrations engaged in to make the situation look better than it was. But the suggestion that three consecutive administrations “hid the truth for two decades” is simply not true. Even when American officials tried to put the best face on a bad situation, they didn’t pretend there was no bad news. Consider the testimony of Gen. David Petraeus in March 2011. He told Congress optimistically that “the past eight months have seen important but hard-fought progress,” as indeed they had. But he also said that progress remained “fragile and reversible,” that “much difficult work” lay ahead, and that there had been “setbacks as well as successes.”

Any cautious optimism advanced by successive administrations was more than matched by members of Congress from both parties. At the same hearing where Petraeus testified, Senate Armed Services Committee Chairman Carl Levin (D-Mich.) reported, on the basis of his own visit to Afghanistan in January 2011, that the Afghan people in former Taliban strongholds were “returning to villages” and had “growing confidence in the ability of Afghan and coalition forces to provide security.” Members of Congress, and especially Democrats, were also enthusiastic about nation-building. Congress repeatedly demanded greater civilian efforts to complement military action, approving billions of dollars in aid and constantly pressing the administration to beef up such efforts. This aid also enjoyed public support. If nation-building in Afghanistan was a mistake, it was a mistake that lots of people made.

The fact was, no one was under any illusions, then or later, that an outright victory was close at hand. Even as Petraeus was making his highly qualified assessment of progress, U.S. intelligence officials were also testifying publicly on their concerns about whether the Afghan government had the ability to take over responsibility for governing. The head of the Defense Intelligence Agency observed at the time that, despite the surge of U.S. troops, there had been “no apparent degradation in” the Taliban’s “capacity to fight” and that its forces remained “resilient” and would be “able to threaten U.S. and international goals in Afghanistan through 2011.”

The notion that Americans were duped into believing that all was well in Afghanistan is belied by polls throughout the war. Only a small minority ever said they were “confident” that U.S. policies in Afghanistan would eventually succeed. In the summer of 2005, 75 percent were either “not confident” or “not sure.” Five years later, in 2010, that share was up to over 80 percent, while only 12 percent expressed confidence.

Yet despite this, a majority of Americans consistently supported continued involvement, and in 2009 a substantial majority supported Obama’s dramatic increase in troops. Indeed, voters had a higher opinion of Obama’s Afghanistan policy than of his handling of the economy and health care. Like the administration, the public and Congress knew the war wasn’t going particularly well but opposed departing and favored a greater U.S. commitment. By and large, Americans were all in it together, even if most have a hard time remembering that now.

From the beginning, the effort in Afghanistan faced severe constraints, many self-imposed. Afghanistan was a classic case, repeated many times throughout American history, of a United States with one foot out the door from the moment of intervention. This started with the Bush administration. The common theme of Afghanistan and Iraq was the belief by Rumsfeld and his subordinates that both interventions could be sustained without a large commitment of U.S. forces. Perhaps this belief could be attributed to hubris, but it was really just an effort to keep the American footprint to a minimum. Gen. Dan K. McNeill, the commander of coalition forces in Afghanistan in 2002-2003, told government interviewers that his superiors at the Pentagon mainly cared about keeping a lid on the number of deployed U.S. troops. Rumsfeld in particular would become exercised at any mention of additional forces. Some argued for more troops, but as Richard Haass, who was one of them, later recounted, “There was a profound sense of a lack of possibility in Afghanistan.” Instead, as in Iraq, the Pentagon worked to build an Afghan army capable of taking over. U.S. officials tended both to inflate the numbers and exaggerate the capabilities of the Afghan army. Why? To demonstrate that there was no need for more American troops or a more extended commitment. When the British commander of NATO forces in Afghanistan told Rumsfeld in 2006 that “we don’t have enough troops and resources,” Rumsfeld responded, “General, I don’t agree. Move on.”

Whatever chance of success the United States might have had was not improved by this half-in/half-out approach. The Taliban could see how eager the Americans were to get out and so bided its time. But as significant was the effect on America’s partners in Afghanistan. The very uncertainty of the American commitment worked at cross-purposes with the effort to build a government and an army that could stand on their own. As one American who served in Afghanistan has pointed out, one of the consequences was to increase corruption. “Our consistent messaging that we were on our way out of Afghanistan encouraged Afghans in positions of power to embrace corruption — specifically, the siphoning of resources for personal gain — as the one clear and sure means of survival. Corruption became a financial contingency plan, the choice any reasonable Afghan would make to ensure a safe future for their children.” Afghan fighters also had to make choices. They had barely held on in the fight against the Taliban with American help, including air support; why imagine that they could hold on without it? No one in the U.S. government ever believed the Afghan army was ready to stand on its own. Officials misjudged only the rapidity of its collapse, which proved embarrassing but should not have been surprising. In any case, it seems a bit unfair to say that America’s Afghan partners were simply “rotten.” Their lives depended on making the right judgment about American staying power, and that was always in doubt.

And it was not just the Afghans who had to make such calculations. Among the biggest obstacles to U.S. policy was Pakistan’s continuing support for the Taliban. Top Pakistani officials made no secret of the fact that they were hedging their bets. As the head of the Pakistani intelligence service told then-Ambassador Ryan Crocker, one day “you’ll be done with us, but we’re still going to be here … and the last thing we want with all of our other problems is to have turned the Taliban into a mortal enemy, so, yes, we’re hedging our bets.” As Crocker said in 2016, the only way to have compelled a different set of calculations would have been to make clear that there was no calendar for withdrawal, that the United States was prepared to keep its forces in Afghanistan for as long as necessary. As Crocker put it, “Americans are short-term. Our adversaries count on that, and our allies fear it.” One can only wonder how the various actors might have responded had the Bush administration and its successors said the United States was prepared to stay in Afghanistan for 20 years, instead of spending 20 years with one foot always out the door.

The further irony is that Americans have maintained troops in other countries for decades. They have kept troops in Korea for 70 years, guarding against the resumption of a war that has never formally ended and that could erupt again at any moment. They have kept American troops on the front lines of the Cold War in Europe and elsewhere in Asia for even longer. There were American forces in the Balkans for more than a decade. The fact is, Americans will keep troops in distant theaters for decades, so long as casualties are minimal.

Could things have gone differently in Afghanistan? Possibly, although that seems unlikely given the proclivities of all the parties involved. Successive U.S. administrations believed the likely price of lasting success in Afghanistan was higher than the American people wanted to pay, especially as the fear and anger after 9/11 faded. But the price of withdrawal was also too high. Under the circumstances, it was not surprising that successive presidents chose the route they did. And though there can be much second-guessing about both strategy and tactics, this was not one of those cases where the answer was obvious and only ideologues could not see it. So why the brutal recriminations? Why does every American setback have to be a morality tale, a search for scapegoats and an indictment of American foreign policy in general? The United States intervened in Afghanistan for perfectly good and understandable reasons after 9/11 and then did not know how to extricate itself with an acceptable outcome. Why has this been treated by so many as a tale of sin and hubris? Why has the “war on terror” come to be viewed as a symptom and for some the source of much of America’s troubles today?

In fact, the “war on terror” has been successful — astoundingly so. If you had told anyone after 9/11 that there would not be another major attack on the U.S. homeland for 20 years, few would have believed it possible. The prevailing wisdom at the time was that not only would there be other attacks, but they would be more severe. In 2004, Harvard’s premier foreign policy expert, Graham Allison, predicted that it was “more likely than not” that terrorists would explode a nuclear weapon in the United States in the coming decade. What former Obama and current Biden officials Rob Malley and Jon Finer observed three years ago remains true today: “No group or individual has been able to repeat anything close to the devastating scale of the 9/11 attacks in the United States or against U.S. citizens abroad, owing to the remarkable efforts of U.S. authorities, who have disrupted myriad active plots and demolished many terrorist cells and organizations.”

That this fact is rarely noted as Americans argue about Afghanistan is remarkable. Does anyone think these efforts would have been as successful if after 9/11 the United States had left the Taliban and al-Qaeda in place for all these years? And it is interesting that so many Americans now believe the price has been too high. As often happens, the fact that the United States hasn’t been hit again tends to reinforce the idea that there never was a serious threat to begin with, certainly not serious enough to warrant paying such a price. But this is again the difference between living history forward and judging history backward. If someone had told Americans after 9/11 that they could go two decades without another successful attack but that it would cost 4,000 American lives and $1 trillion, as well as tens of thousands of Afghan lives, would they have rejected it as too high? Likely not.

When Americans went to war in 2001, most believed that the dangers of inaction had become too great, that threats of both international terrorism and weapons of mass destruction were growing, and that serious efforts had to be made to address them. Today, many Americans increasingly believe that those earlier perceptions were mistaken or perhaps even manufactured. With America’s departure from Afghanistan, we may begin to learn who was more right.