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

Biden Just Made a Historic Break With the Logic of Forever War

But will he really end the United States’ other open-ended conflicts?

By , a senior fellow in the American Statecraft Program at the Carnegie Endowment for International Peace.
A U.S. soldier during Operation Khanjari in Afghanistan.
A U.S. soldier during Operation Khanjari in Afghanistan.
A U.S. soldier from 2nd Marine Expeditionary Brigade takes up a fighting position during the start of Operation Khanjari in Main Poshteh, Afghanistan, on July 2, 2009. Joe Raedle/Getty Images

Leaving Afghanistan

For two decades, the United States waged a war in Afghanistan that it could not win but would not quit. “I do not support the idea of endless war,” U.S. President Barack Obama declared in 2015—as he commanded U.S. forces to continue fighting one.

For two decades, the United States waged a war in Afghanistan that it could not win but would not quit. “I do not support the idea of endless war,” U.S. President Barack Obama declared in 2015—as he commanded U.S. forces to continue fighting one.

The United States’ post-9/11 wars have been long, but it was not mainly their longevity that gave rise to the objection, on both the left and the right, that they had become endless. The problem lay in the nature of the objectives U.S. leaders chose to pursue. Extravagant goals, unnecessary to secure the United States, could not be fulfilled. The United States continued fighting anyway. The so-called “war on terror” was endless by definition, “terror” being a sensation and a tactic that will always be part of human experience. For Americans, war came to appear normal, inescapable, eternal, even if its burdens fell on few of their own. Somehow the most powerful country on earth seemed incapable of being at peace.

In Afghanistan, successive presidents sought to build a new state and sustain it against insurgents. This was a mission that no foreign military could achieve, unmistakably so after a surge to 98,000 U.S. troops and thousands of troops from other NATO countries failed to suffice. From then on, the United States was fighting only to delay defeat. It had two coherent options: Keep on forever or stop at once.

President Donald Trump escalated in Afghanistan before cutting a deal to put the United States’ war on a path to termination. But it is his successor Joe Biden, the creature of Washington, who has broken with the logic of endless war, at least in this one exemplary case. President Biden has not just decided to withdraw all U.S. troops, scrapping his campaign plan to leave residual forces behind. He has also delivered a methodical debunking of the forever-war mindset that has prevailed for decades. After the United States ends one endless war, what might come next?


When Biden addressed the nation on Wednesday, he confined himself to Afghanistan. He nonetheless delivered no less than a thorough indictment of bipartisan rationales for endless war.

Biden was not content to act as a reluctant steward of the withdrawal agreement handed to him by his predecessor. Nor did he merely rank other priorities above the stakes in Afghanistan. Biden went further, arguing that Washington’s cause for war had long been wrong. The United States originally acted, Biden said, for a just and achievable purpose: to “root out al Qaeda” and prevent further attacks on the U.S. homeland. Once the United States fulfilled those objectives, it had no business remaining. “We delivered justice to [Osama] bin Laden a decade ago,” he said, “and we’ve stayed in Afghanistan for a decade since.”

Biden barely referenced the stated reasons for which the United States had kept fighting, among them building an Afghan state and protecting human rights. He treated those goals as superfluous at best. In one way or another, they were attempts to make the United States indispensable to the destiny of Afghanistan. Biden rebuked this view flatly. “Only the Afghans have the right and responsibility to lead their country,” he said. While affirming that the United States would continue to help Afghanistan through nonmilitary means, Biden implied that the United States should wage war only where necessary for its own security.

On his most consequential foreign-policy decision to date, Biden surprised—and he might surprise again.

Critics of Biden’s decision obscured the difference between U.S. and Afghan interests and presumed that U.S. participation in war would benefit Afghanistan. David Petraeus, the former commanding general in Afghanistan, objected that “ending U.S. involvement in an endless war doesn’t end the endless war” for Afghans. But what took precedence for Biden was ending the endless war for Americans. That was his fundamental responsibility as president and the one outcome under his control. And in pledging U.S. support for peace talks between the Afghan parties, Biden also implied that detractors like Petraeus abused the term “endless war.” Once the U.S. military left, Afghanistan would in fact be fighting a classic civil war to establish political control over territory. Such a war might yet prove long and brutal, but it would also be capable of resolution. It was the United States that was fighting a forever war and the United States that had the power to stop.

Indeed, Biden treated endless war as inherently unacceptable. Having determined that the United States could not win the war it was currently fighting, he decided that it must quit. He has given the order to withdraw U.S. forces regardless of conditions on the ground. As he explained: “We cannot continue the cycle of extending or expanding our military presence in Afghanistan, hoping to create ideal conditions for the withdrawal and expecting a different result.” Here Biden rejected the position that the U.S. military could make a “modest” and “sustainable” commitment, in the words of Petraeus, in something like perpetuity. By recounting the 2,448 U.S. service members killed and 20,722 wounded in Afghanistan operations, Biden showed he considered such sacrifices to be neither modest nor sustainable. Even more sweepingly, however, he dismissed open-ended war on principle. If he could not give U.S. troops an objective they could define and fulfill, he had a duty to bring the troops home.

Biden made a final argument pregnant with meaning for the United States’ role in the world. “I know there are many who will loudly insist that diplomacy cannot succeed without a robust U.S. military presence to stand as leverage,” he acknowledged. A decade of experience proved otherwise. “Our diplomacy does not hinge on having boots in harm’s way—U.S. boots on the ground,” he said. “We have to change that thinking.” Biden alluded to a general mistake in U.S. calculations: Diplomacy—and with it, perhaps, the promotion of values and rights—did not require armed force to be effective. In fact, force could inhibit the engagement that counted. It could turn U.S. troops, Biden warned, into a “bargaining chip between warring parties in other countries.” Endless war entangled the United States. For Biden, it was past time to end it.


Confronted with a concrete decision in Afghanistan, Biden dispensed with the logic of endless war on no uncertain terms. But logic is one thing, policy another. The administration hardly seems poised to dismantle Washington’s forever war in the greater Middle East and beyond. Biden indicated as much in his speech. To justify leaving Afghanistan, he asserted his determination to combat a terrorist threat that has become “more dispersed, metastasizing around the globe.” He named four organizations to target across two continents. His administration just requested a $715 billion annual budget for the Defense Department, presumably not for the purpose of retracting U.S. military power globally. When Biden proclaims that “America is back,” he seems to mean to restore the post-Cold War grand strategy of divvying up the world into allies and adversaries and shouldering military burdens toward both. Whether such an approach could ever leave the United States at peace is a fair question. Even in Afghanistan, it will take fortitude for Biden to execute his withdrawal. Drone strikes and special operations raids—surely part of endless war—could continue.

And yet, on his most consequential foreign-policy decision to date, Biden surprised. He might surprise again. As he evaluates U.S. counterterrorism operations and reviews the U.S. force posture, he has established standards to apply to himself—and for others to apply to him. If U.S. ground troops are to remain in Iraq and Syria, why would Biden consider their mission, currently to prevent a hypothetical future resurgence of the Islamic State, any more verifiable and achievable than the mission he just terminated? What threat do terrorist groups currently targeted in sub-Saharan Africa truly pose to the U.S. homeland? Why try to sanction North Korea into submission forever, or until it relinquishes the one guarantee it has for its security: nuclear weapons? And so on.

Suddenly, by Biden’s own logic, the United States has acquired an array of endless wars it might end and new ones it might prevent.

After Afghanistan, the forever war goes on. But for the first time, a U.S. president has peered into its essence and said: no more.

Stephen Wertheim is a senior fellow in the American Statecraft Program at the Carnegie Endowment for International Peace and the author of Tomorrow, the World: The Birth of U.S. Global Supremacy. Twitter: @stephenwertheim

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