Few will say it, but the facts are indisputable: America’s war in Afghanistan has failed. There comes a time when persisting in a lost cause amounts to foolishness, indeed irresponsibility. That time has arrived.

Washington’s minimal goals were to vanquish the Taliban, root out Al Qaeda and build a stable, effective government whose army and police would eventually fight the Taliban independently and successfully while maintaining law and order across the land. These objectives have not been meet.

Not for want of effort, mind you. The evidence leaves no doubt that the United States has made an enormous effort.

Let’s begin with the investment in time.

Nearly fifteen years and counting, the war in Afghanistan has become America’s longest. Airstrikes against the Taliban government, undertaken along with the British, commenced in October 2001. American ground troops, 1,300 in number, arrived there in November 2001. By 2010, there were one hundred thousand. A steady cutback started in 2011, pursuant to a decision by President Obama, though some 9,800 still remain, despite the responsibility for fighting the Taliban and securing the country having been transferred to the Afghans in June 2013.

American soldiers may no longer be in the thick of day-to-day battle, but they continue to advise and train Afghan security forces, and to conduct “counterterrorism” operations. Moreover, when Afghan units are besieged, as happened most recently in Tirin Kot, the capital of Uruzgun province, they are forced to call in American airstrikes.

Clearly, then, the claim that not enough time has been invested can’t stand.

Yes, the United States and its allies have helped forge the new 343,900-person Afghan National Security Forces (ANSF), which includes the 185,000-strong Afghan National Army (ANA). Yet after nearly a decade and a half of training, the Afghan military and police still cannot hold their own against the Taliban, which has far fewer fighters (25,000-30,000 being the maximum estimate) and much less firepower. The balance on the battlefield has become far less favorable to the Afghan government since 2013. (More on that later.)

The financial ledger points to an equally impressive effort.

The figure that typically emerges in estimates of what the Afghanistan and Iraq wars have cost is $2 trillion. As Linda Bilmes has shown, that sum results from confining the calculations to military expenditures narrowly defined. If current and long-term costs created by health care for the troops—many have suffered serious mental and physical injuries—death benefits to military families, and interest owed for money borrowed to fund the campaigns are included, the eventual price tag will be more like $4–6 trillion. Similarly, Neta Crawford, who adds in expenditures in Pakistan and Syria as well as for homeland security, reckons the cost at $4.79 trillion, as of 2016.

Both wars were touted as essential for our national security. Yet amidst all the patriotic discourse and displays that followed 9/11, American leaders didn’t see fit to insist that taxpayers do their bit, even as American soldiers were asked to risk life and limb. What followed amounts to war by credit card.

It’s hard to pin down the proportion of the $4–6 trillion attributable to the Afghan war, so let's be conservative and assume a 30 percent share. That still amounts to between $1.2 and $1.8 trillion.

Now let’s consider effort defined as America’s share of the contribution of all states that have participated in the fight against the Taliban.

The Afghan war has been presented as a venture by a large coalition, and that’s true in some respects. The International Security Assistance Force (ISAF), created under a UN mandate in December 2001, eventually included 51 countries, with NATO assuming leadership in 2003. Initially, ISAF’s assignment was confined to Kabul and its environs. But between December 2003 and October 2006 it expanded in stages to the rest of the country, and included fighting the Taliban, training and advising Afghan units, and protecting the Provincial Reconstruction Teams (PRTs).

In 2011, around which time ISAF reached its numerical peak, American accounted for 68 percent of its 132,203 troops. By 2016, the coalition’s numbers had fallen to 12,930, of which 7,006, or 54 percent, were American—not counting the additional US troops operating in Afghanistan outside NATO command. Moreover, in 2016, only six ISAF states (Britain, Georgia, Germany, Romania, Italy and Turkey) provided more than five hundred troops; twenty-seven contributed fewer than one hundred.

It does not diminish the efforts and sacrifices made by the troops of these other countries to recognize what the facts show: the United States has borne the brunt of the burden in Afghanistan. No statistic better illustrates this than the one pertaining to the ultimate military sacrifice. Of the 3,520 ISAF troops killed in Afghanistan so far, 2,384—68 percent—have been Americans.

Sometimes, the case for not leaving Afghanistan includes examples of economic and social achievements: various development-related projects, the increase in school enrollment, more medical clinics, and so on.

But the United States did not begin this campaign to promote economic and social advancement in Afghanistan. And even if one acknowledges that there have been some laudable results, the other side of the story bears telling. As a report issued by the Office of the Special Inspector General for Afghanistan Reconstruction (SIGAR) noted, calculated in dollars adjusted for inflation, economic assistance to Afghanistan ($109 billion) has already exceeded what was spent on the post-World War II Marshall Plan ($103.4 billion), which helped rebuild sixteen war-torn European countries.

On top of that, a significant amount of the money allocated for economic and military assistance in Afghanistan has been lost to fraud, theft, uncompleted or useless projects and others that amount to Potemkin villages—in all about $17 billion since 2009 according to audits done by SIGAR. The American side bears plenty of responsibility for the misuse of these funds, but it also reflects deeply rooted problems in Afghanistan, notably corruption (the country placed third from the bottom in Transparency International’s 2015 ranking) and ineffectual institutions.

Furthermore, the side effects of this massive inflow of foreign aid have not been positive. The appreciation of the Afghan currency has placed domestic businesses and locally made products at a price disadvantage relative to imports. That in turn has hampered job creation and in part also explains why Afghanistan badly trails many other developing countries in revenue collection as a percentage of GDP.

So whether measured in time spent, the proportion of the total burden shared, or the amount of blood and treasure expended, the American failure in Afghanistan cannot be attributed to insufficient effort or impatience.

President Obama recognizes this, as he does the futility of ramping up the effort and persisting indefinitely.

In 2011, by which time there were one hundred thousand U.S. troops in Afghanistan, he announced a phased reduction that would culminate in winding down the war by the end of his term in 2017. By 2013, when the task of fighting the Taliban had been handed to the ANSF, the number of American troops had been reduced to forty-six thousand. By March 2015, it fell to 9,800. The president’s goal was to reach 5,800 by the end of 2017, but that target will now be missed given the gains made by the Taliban of late.

So the good news is that America’s Afghan war has been wound down since 2011. But what has this massive, extended effort achieved?

Certainly not the emergence of an effective Afghan state.

Neither under the current president, Ashraf Ghani, nor during the tenure of his predecessor, Hamid Karzai, has there been anything resembling an effective government with national reach and local purchase. Moreover, it has become less cohesive and more fractious.

When the results of the 2014 presidential election that transferred power from Karzai to Ghani were announced, the opposition candidate, Abdullah Abdullah, immediately cried foul. He and his followers still believe they were cheated out of victory. (Of Pashtun and Tajik parentage, Abdullah gained the overwhelming majority of Tajik votes. But he also won support from Pashtuns—who constitute a plurality in Afghanistan—despite the advantage Ghani enjoyed as a Pashtun, as well as Uzbeks and Hazaras.)

To avert a political crisis, Secretary of State John Kerry brokered a power-sharing pact that year—never mind that the Afghan constitution provides no basis for its provisions. Abdullah was named “Chief Executive,” effectively second in command, a prime minister of sorts responsible for day-to-day management.

But the two men continue to undermine one another. Ghani sidelines Abdullah on key decisions, acting independently. Abdullah denounces him . . . and so it goes, without surcease. Just last month, Abdullah proclaimed Ghani “unfit” to rule and complained that the two rarely met. To call this a “national unity government” amounts to a cruel joke.

The Ghani-Abdullah accord was supposed to have paved the way for electoral reforms, local elections, and the convening of a Loya Jirga (a grand assembly of notables) to formalize and legitimize the post of Chief Executive—all by September-October 2016. None of this happened, nor will it because a political war rages at the pinnacle of Afghanistan’s political order.

Warlordism, now deeply embedded in Afghanistan’s politics, creates another source instability, even as it provides relatively good governance in some locales.

Strongmen with private militias exist at all levels of the Afghan polity. Some have parlayed their clout to secure top posts in the central government. The Hazara warlord Karim Khalili was Hamid Karzai’s Vice President. The Uzbek chieftain Abdul Rashid Dostum, who has a blood-curdling reputation for cruelty, currently serves as Vice President, no matter that Ghani once called him a “known killer.” (Members of Dostum’s Junbish militia, which has a long record for brutality against civilians, recently attacked a Tajik group, prompting security forces to intervene.)

Among the warlords who wield local power, Atta Mohammed Noor, a Tajik and the governor of Balkh province, where he has promoted order and economic development, may be the best known to outsiders. He and others like him represent an entrenched pattern: powerful men with armed retainers who make tactical alliances with the state (and one another) and, though appointed by the president, are ultimately a law unto themselves.

The prospect of a savvy Kabul government controlling the main levers of politics and devolving power to warlord rulers while also manipulating their rivalries artfully makes for an intriguing idea. But with infighting in Kabul and an insurgency on the upswing, that’s not a feasible model for political equilibrium in Afghanistan. Heightened war will make the central government weaker, the local warlords stronger.

As for the balance on the battlefield, on the one hand American and Afghan forces have inflicted heavy losses on the Taliban since 2002. Many of its senior commanders and leaders have been killed, most recently (in May) Mullah Akhtar Mohammad Mansour, the movement’s Emir. And feuds have divided its ranks, threatening the unity of an insurgency that has always been riven by factionalism.

On the other hand, Taliban fighters not only remain standing, they now control, or have established a presence in, more of Afghanistan’s territory than at any time since the war began, including in the north and west, outside their Pashtun bastions in the south and east.

Only in a clutch of Afghanistan’s thirty-four provinces (such as Balkh, Bamyan, Ghor, Daykondi, Jowzjan and Samangan) do the Taliban not pose a major threat. Yet even in these places they make their presence felt, assassinating or abducting officials and police and punishing ordinary folk pitilessly for violating the movement’s draconian definition of morality.

The lack of a Pashtun majority in these areas explains their relative stability. In recent years, however, the traditionally Pashtun-based Taliban insurgency has attracted, and inducted into leadership positions, local and central, Tajiks, Uzbeks and Turkmen who have turned against the government for various reasons. These include the state’s corruption and economic failures and the cruelties of locally recruited militias on which it relies to bolster security, including the so-called Afghan Local Police, an American-inspired creation.

The Kabul government has been forced to yield considerable ground over the past two years—five percent in the first five months of 2016 alone—and now controls only two-thirds of the country. The Taliban controls or contests the rest and according to some assessments may hold a much bigger percentage. The number of ANA soldiers killed in battle increased by 28 percent between 2014 and 2015, and the force has been stretched thin because it has had to fight on multiple fronts.

Though the Taliban has taken a pounding for almost fifteen years, they have displayed doggedness, regained momentum and remain unwilling to lay down their weapons. Nor do they seem in any hurry to negotiate a peace. Mansour’s successor as Emir, Mullah Haibatullah Akhunzada, has vowed to continue the jihad. The Taliban won’t rule Afghanistan again, but they will be part of its political future—in war or peace.

After fifteen years of fighting and the expenditure of trillions of dollars, this is the reality America faces in Afghanistan. Whatever it is, success it is not.

Yet many military experts and former officials urge that we must stay the course. But if the United States could not do better than it has after making a prolonged, substantial and expensive attempt, what are the odds of success, say, five years down the line?

Those convinced that ending the war would be a big mistake make several points to back their claim.

America’s credibility will suffer, they say. (Within our foreign policy establishment, credibility becomes the all-purpose rationale when all other arguments ring hollow.) As it happens, the commonplace claim that abandoning a failed venture emboldens adversaries and demoralizes allies stands on a thin foundation of evidence. And the underlying logic resembles that of a man who persists in banging his head against a wall, refusing to stop for fear that onlookers will doubt his mettle if he does. He can reasonably anticipate but one result from such a demonstration of resolve: a huge headache, perhaps even a serious head injury.

Another argument made for keeping troops in Afghanistan rests on the prediction that their departure will turn it into an arena for freewheeling competition and conflict among neighboring countries. But as I have written elsewhere, that’s precisely what Afghanistan has been ever since the Taliban was toppled in 2001, with India, Pakistan and Iran being the main contenders. And it will continue to be, no matter what the United States does because, for many reasons, starting with geography, Afghanistan’s political trajectory matters far more to these countries than it does to the United States.

Then there’s the claim that outsiders’ rivalry over Afghanistan could lead to a war. India and Pakistan, for instance, might clash if the United States fails to stick around in Afghanistan and restrain them—and their collision could escalate, leading to the use of nuclear weapons.

There may well be another war between these two countries, but the spark won’t be their competition in Afghanistan, but rather an armed confrontation in Kashmir or a terrorist attack in a major Indian city that New Delhi traces to Islamabad. Neither scenario will be made less likely by the United States retaining a military presence in Afghanistan. And a spiral into nuclear war becomes a high probability outcome only if one assumes that the logic of deterrence, which has restrained other pairs of adversaries, somehow cannot apply to India and Pakistan.

The most frequent reason adduced for a continued American military role in Afghanistan involves the specter of Al Qaeda planning another 9/11-style attack from there.

Though Al Qaeda has absorbed serious blows, starting in Afghanistan in 2001, it has proved resilient and adaptive and remains a force to be reckoned with. It has established branches in many countries, any one of which could serve as a venue for hatching terrorist plots. The endless projection of American military power into various places in an effort to terminate terrorism resembles a game of whack-a-mole more than it does a wise strategy.

The 9/11 operation was indeed planned from Afghanistan. But the elements essential to its implementation—skyscrapers, airplanes, a modern banking system and flight training—all required access to modern, industrialized societies. A policy that secures the American homeland using multiple means, and with due regard for the delicate balance between ensuring citizens’ safety and protecting their liberty, will work better than employing the blunt instrument of military power across the world, and without any apparent endpoint.

The use of American military might in Iraq, Libya, Pakistan, Somalia and Afghanistan has ended up created circumstances and sentiments favorable to those who recruit young people and turn them towards terrorism. Moreover, the destruction of regimes and the inability to produce order thereafter has produced power vacuums that religious zealots, terrorists, warlords and ethnoreligious militias have filled. Civil war and terrorism have followed. The distribution of vast numbers of weapons, intended for armies or militias being trained by the United States, has led to their vanishing and ending up in the wrong hands or on the international arms bazaar for sale to the highest bidder.

The proposition that the American intervention in Afghanistan has made Afghans, neighboring states, or the United States more secure seems shaky to say the least. So does the recommendation that doing more of the same will eventually produce a better outcome.

In short, the war in Afghanistan has failed. It was a mistake to deploy troops there and to attempt something that the United States, its impressive resources notwithstanding, has been unable accomplish save in the special instances of Germany and Japan after World War II: remaking entire societies. While this error may be clearer in hindsight, it should now be evident that the plan to build a new Afghanistan has not succeeded—and indeed cannot.

None of the parties, internal or external, will find a military path to victory in Afghanistan. The violence can be ended only through a political settlement involving the warring parties and states, from the region and beyond, with stakes and influence in that country. The United States can and should remain active in the difficult and uncertain search for such a solution. It does not face a choice between clinging to the current policy and walking away.

Rajan Menon is Anne and Bernard Spitzer of International Relations at the Powell School, City College of New York/City University of New York. He is a senior research fellow in the Saltzman Institute of War and Peace Studies at Columbia University. He is the author, most recently, of The Conceit of Humanitarian Intervention (Oxford University Press, 2016).

Image: U.S. Army soldiers prepare to conduct security checks near the Pakistan border at Combat Outpost Dand Patan in Afghanistan's Paktya province on Feb. 29, 2012. Wikimedia Commons/U.S. Army