Argument

An expert's point of view on a current event.

The Strategic Logic of a Forever War

The United States should have ignored sunk costs in Afghanistan and maintained a light military footprint.

By , an associate professor at the Naval Postgraduate School, and , the managing partner at One Defense and a senior advisor at the Atlantic Council.
Pfc. William Berczik stands on top of a Stryker vehicle in the desert near Kandahar, Afghanistan, on March 6, 2014.
Pfc. William Berczik stands on top of a Stryker vehicle in the desert near Kandahar, Afghanistan, on March 6, 2014. Scott Olson/Getty Images

Leaving Afghanistan

President Joe Biden’s precipitous withdrawal from Afghanistan was based on the argument that the U.S. government needed to cut its losses and end a “forever war.” Proponents of this view maintain that the war in Afghanistan was a costly failure and the United States needed to stop throwing good money after bad. But this argument is flawed—based on what economists call the “fallacy of sunk costs,” a common pathology where past, unrecoverable investments are taken into consideration when making decisions about the future.

Rationally, the losses on such past investments should be ignored. Take, for instance, the example of a small business owner wrestling with the weight of years of personal investment in her business and repeated decisions to stick it out in the face of losses. She decides to close down just as the business in question begins to turn a profit and money starts to trickle into the bank account for the first time in years.

Business schools teach their students that this type of pathology—which might encourage withdrawal from a business venture due to past losses—needs to be overcome with cold logic, and that all decisions about continued investment need to focus solely on the expected utility of any future actions while ignoring unrecoverable costs incurred previously.

President Joe Biden’s precipitous withdrawal from Afghanistan was based on the argument that the U.S. government needed to cut its losses and end a “forever war.” Proponents of this view maintain that the war in Afghanistan was a costly failure and the United States needed to stop throwing good money after bad. But this argument is flawed—based on what economists call the “fallacy of sunk costs,” a common pathology where past, unrecoverable investments are taken into consideration when making decisions about the future.

Rationally, the losses on such past investments should be ignored. Take, for instance, the example of a small business owner wrestling with the weight of years of personal investment in her business and repeated decisions to stick it out in the face of losses. She decides to close down just as the business in question begins to turn a profit and money starts to trickle into the bank account for the first time in years.

Business schools teach their students that this type of pathology—which might encourage withdrawal from a business venture due to past losses—needs to be overcome with cold logic, and that all decisions about continued investment need to focus solely on the expected utility of any future actions while ignoring unrecoverable costs incurred previously.

The U.S. presence in Afghanistan prior to its withdrawal had, in fact, become both relatively effective and efficient. Though the financial costs of the conflict were still significant, they had been falling relatively consistently since their height in 2011. A decade ago, the U.S. government was spending $114 billion on the Afghan conflict; this year, it was just $14 billion. In American lives, the costs had been dropping even more steeply. Although 1,833 U.S. troops were killed in action in Afghanistan from October 2001 to December 2014, only 77 casualties occurred after Jan. 1, 2015, including the 13 killed in the Kabul airport evacuation. Every life has incalculable value, of course; but to put that number into perspective, consider that the city of Chicago recorded 105 homicides in July 2021 alone.

Afghan troops were doing most of the frontline fighting and taking the brunt of the casualties. At the beginning of the summer, there were roughly 2,500 U.S. forces in Afghanistan, a small fraction of the 100,000 troops deployed at the height of the surge. This modest contingent—focusing on counterterrorism, training, and advising—had enabled Afghan security forces to hold all major population centers in the country. It supported increasingly capable Afghan special operations forces, and enabled Afghan-piloted aircraft to punish the insurgents.

The human cost of the conflict to both Afghan civilians and military forces, however, was very high, numbering well over 100,000 dead. (It is little wonder that, during the past month, the Taliban have enacted appalling reprisals largely against members of the Afghan Special Forces and the pilots who flew the ferocious Super Tucano ground attack planes that pounded the Islamist group on a daily basis.)

Nevertheless, after 20 years of bloodshed and enormous investment, the United States had arrived at a point where its presence was at least close to being strategic, sustainable, and effective in giving Afghans an opportunity to build a lasting peace. Instead of making that clear-eyed assessment, however, it seems the Trump and Biden administrations focused largely on what they had already lost—the sunk costs.

While many pilloried Biden’s Aug. 31 speech to the American public, during which he defended the ending of the “forever war,” he was merely delivering on his campaign promise and reinforcing the previous administration’s agreement with the Taliban.

A more rational approach would have been to maintain a small military footprint in Afghanistan—and to make that presence more cost-effective. That in turn would have required a fundamental shift in American strategy, moving away from the naive idealism that characterized most of the Afghan war—an idealism shared by neoconservative and liberal administrations—to a more calculated realism.

Instead of making a clear-eyed assessment, the Trump and Biden administrations focused largely on what they had already lost—the sunk costs.

A cursory review of the Pentagon’s 2011 overseas contingency operations budget request shows $89 billion spent on U.S. combat operations, $12 billion on force protection of U.S. personnel in country, and $21 billion on covering the damage to U.S. forces who had returned from theater. And this was just for one year. Meanwhile, the U.S. spent roughly $133 billion on nation-building programs, such as reconstruction of infrastructure and aid programs. All of this had largely been eliminated in 2021.

To be clear, such a limited presence would not have led to some crisp military victory, let alone the Quixotic nation-building goals of the war’s early years. That was never possible. But as analysts try to draw the proper lessons about Afghanistan to inform future policies, it’s worth considering whether the investments made could have been maintained at a reasonable cost and for strategic purpose.

That strategic purpose would have been threefold: first, maintenance of a robust counterterrorism program conducted under the Freedom’s Sentinel umbrella; second, provision of regional stability and the capacity to shape outcomes in the neighborhood; and finally, enhancement of a range of security and intelligence activities concerning neighboring China and nearby Russia.

Although it’s become fashionable in some circles to frame the war in Afghanistan, not to mention Iraq, as a forever war that had to end, Americans and their allies need to take a more sober look at what informed such a decision. Was it an emotional response to irrecoverable losses already incurred? Or a clear-eyed look at present and future opportunities and dangers?

In the future, a more rational approach would embrace greater realism in U.S. foreign policy: Not every engagement with the world needs to be a perfect reflection of U.S. values and institutions. Being able to treat foreign policy as a tool honed to further the national interest is an approach American leaders need to relearn.

Leo Blanken is an associate professor at the Naval Postgraduate School and author of the book Rational Empires: Institutional Incentives and Imperial Expansion. The views expressed in this article are those of the author and do not reflect the official policy or position of the Department of Defense or the U.S. government.

Stephen Rodriguez is the managing partner at One Defense and a senior advisor at the Atlantic Council. He was deployed to Afghanistan from 2010 – 2011. Twitter: @steverod78

Join the Conversation

Commenting on this and other recent articles is just one benefit of a Foreign Policy subscription.

Already a subscriber? .

Join the Conversation

Join the conversation on this and other recent Foreign Policy articles when you subscribe now.

Not your account?

Join the Conversation

Please follow our comment guidelines, stay on topic, and be civil, courteous, and respectful of others’ beliefs. Comments are closed automatically seven days after articles are published.

You are commenting as .

More from Foreign Policy

The Taliban delegation leaves the hotel after meeting with representatives of Russia, China, the United States, Pakistan, Afghanistan, and Qatar in Moscow on March 19.

China and the Taliban Begin Their Romance

Beijing has its eyes set on using Afghanistan as a strategic corridor once U.S. troops are out of the way.

An Afghan security member pours gasoline over a pile of seized drugs and alcoholic drinks

The Taliban Are Breaking Bad

Meth is even more profitable than heroin—and is turbocharging the insurgency.

Sviatlana Tsikhanouskaya addresses the U.N. Security Council from her office in Vilnius, Lithuania, on Sept. 4, 2020.

Belarus’s Unlikely New Leader

Sviatlana Tsikhanouskaya didn’t set out to challenge a brutal dictatorship.

Taliban spokesperson Zabihullah Mujahid

What the Taliban Takeover Means for India

Kabul’s swift collapse leaves New Delhi with significant security concerns.