President Biden speaks from the Treaty Room of the White House on Wednesday about the withdrawal of the remainder of U.S. troops from Afghanistan. Andrew Harnik/Associated Press

WASHINGTON — President Biden announced Wednesday that the United States will withdraw all troops from Afghanistan by Sept. 11, saying in a speech from the White House that the United States had become mired in an endless and increasingly irrelevant conflict that more time and more troops would not resolve.

Biden did not declare a military victory, saying instead that a perpetual presence in the country would not serve U.S. interests. America must focus on a modern landscape of threats that is far different from nearly two decades ago, when the war began in response to the terrorist attacks of Sept. 11, 2001, Biden said.

“I’m now the fourth United States president to preside over American troop presence in Afghanistan. Two Republicans, two Democrats,” Biden said. “I will not pass this responsibility on to a fifth.”

In a sober address from the Treaty Room, the same location where President George W. Bush announced that the war had begun, Biden said the United States has long since achieved the original goals of the war.

“I’ve concluded that it’s time to end America’s longest war. It’s time for American troops to come home,” he said.

President Biden visits Section 60 of Arlington National Cemetery in Arlington, Va., on Wednesday. Biden earlier announced the withdrawal of the remainder of U.S. troops from Afghanistan by Sept. 11, the 20th anniversary of the terrorist attacks on America. Andrew Harnik/Associated Press

Biden punctuated his remarks with a visit to Arlington National Cemetery’s Section 60, where dead from the Iraq and Afghanistan wars are buried.

“Look at them all,” Biden marveled, his voice thick with emotion. He walked a long line of white headstones, then made the sign of the cross before a large wreath. He saluted before turning away.

In his remarks, Biden said that each president who has dealt with the war has given a version of the same rationale for continuing to fight it.

“The main argument for staying longer is what each of my three predecessors have grappled with: No one wants to say that we should be in Afghanistan forever, but they insist now is not the right moment to leave,” he said.

More than 2,000 U.S. service members have died in Afghanistan in a conflict that has cost trillions but often lacked a clear objective.

“We went to Afghanistan because of a horrific attack that happened 20 years ago,” Biden said. “That cannot explain why we should remain there in 2021. Rather than return to war with the Taliban, we have to focus on the challenges that are in front of us.”

Since it became public Tuesday, Biden’s decision has been criticized by many Republicans, who called it reckless or shortsighted. Pulling out U.S. troops, and announcing the specific timetable for doing so, will lead to victories by the Taliban and more terrorist acts, they warned.

Biden’s decision also means the end of a long mission for NATO and other allied forces that entered the fight at the request of the United States.

After a daylong meeting in Brussels with Secretary of State Antony Blinken and Defense Secretary Lloyd Austin, NATO members – who still have thousands of troops in Afghanistan – released a statement saying they, too, would start withdrawing by May 1.

“The United States will never forget the solidarity that our NATO allies have shown every step of the way,” Blinken said at a news conference with Austin and NATO Secretary General Jens Stoltenberg. Saying that the objective of preventing another terrorism attack launched from Afghanistan had been met, Blinken added that “no country could have achieved what we achieved as an alliance, working together.”

Those comments marked a sharp contrast in tone from former President Donald Trump, who often questioned America’s role in NATO.

The allies have long said they could not continue to operate in Afghanistan without U.S. security and logistical support, and a handful of NATO members reportedly questioned the U.S. decision in a closed-door meeting.

Austin, asked whether U.S. military leaders – some of whom were less than enthusiastic about the withdrawal – agreed with the decision, answered indirectly. “What I can tell you is this was an inclusive process and their voices were heard, and their concerns taken into consideration,” he said.

The U.S. withdrawal plan follows a road map established by Trump, who also said that the war had run its course and could not be won in the decisive manner of World War II or other iconic conflicts.

“We’re not really fighting. We’re almost a police force over there. We’re not supposed to be a police force,” Trump said in 2019.

Biden said Wednesday that he supported the original decision to send U.S. forces into Afghanistan, but later came to question the wisdom of tying departure to benchmarks for stability that never came. He noted that it has been nearly a decade since U.S. commandos killed al-Qaida mastermind Osama bin Laden.

“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,” Biden said.

Biden said he had spoken with Bush on Tuesday to tell him of the decision.

The president said he understood the argument that the United States would lose leverage over Taliban insurgents by leaving but noted that staying had not achieved peace.

“We gave that argument a decade,” Biden said. “It’s never proved effective. Not when we had 98,000 troops in Afghanistan, and not when we were down to a few thousand. Our diplomacy does not hinge on having boots in harm’s way, U.S. boots on the ground.”

The United States officially has 2,500 troops in Afghanistan, but there are about 1,000 additional Special Forces personnel in the country.

The experience of military service, either for a president or for his children, has become unusual. George H.W. Bush was the last combat veteran to become president, and Biden speaks often of his son Beau, who served in Iraq and died of cancer in 2015.

At the Arlington visit, reporters asked what the vista of headstones meant to him. “It means that I’m always amazed at generation after generation, the women and men prepared to give their lives for their country,” Biden said.

“It means I have trouble these days ever showing up at a cemetery not thinking of my son, Beau, who proudly insisted on putting on that uniform and going with his unit to Iraq,” he added a moment later.

Biden’s announcement comes as the United States is set to miss the May 1 deadline to leave the country negotiated last year between the Trump administration and the Taliban.

He said the United States will begin departing before that date and conclude its withdrawal before the 20th anniversary of the 9/11 attacks that killed nearly 3,000 people in New York, Washington and Pennsylvania.

“It’s perhaps not what I would have negotiated myself, but it was an agreement made by the United States government, and that means something,” Biden said of the Trump pact, which was criticized by some Democrats as an abandonment of the U.S.-backed elected government in Kabul.

On Wednesday, however, liberal Democrats, including Sens. Bernie Sanders, I-Vt., and Elizabeth Warren, D-Mass., praised the president for moving to end the prolonged conflict.

Some military officials are concerned that a complete departure could lead to more terrorist activity. Biden addressed those concerns in part by vowing to continue to support Afghanistan’s government through diplomatic and humanitarian work.

He said the United States will continue to support both the Afghan government and its armed forces and will support peace talks between the government and the Taliban. Those talks, which began in September as part of the U.S.-Taliban agreement, have made little progress.

Military service members are far from the only Americans who have been enmeshed in the long-running struggle. A sprawling network sprouted in Afghanistan, including government bureaucrats, counterterrorism contractors, think tank scholars and diplomats who wrestled with how to turn the country into a stable, economically viable democracy.

That effort has been gradually downsized, along with the U.S. military force.

While the military had tight control of the overall effort, Barack Obama’s 2009 decision to surge the number of troops came with a vast increase in government-funded civilian efforts. Most of them were coordinated by a new State Department office for Afghanistan and Pakistan, headed by veteran diplomat Richard Holbrooke.

“It was kind of a war office” for everything not directly under the military, said Vali Nasr, who served as Holbrooke’s deputy. With much of its staff drawn from other parts of the government, from the Agriculture Department to the CIA, it tried to build new electricity grids, start a pomegranate-growing cooperative and stem Afghanistan’s robust heroin industry, among many other efforts.

What it did not do was allow Holbrooke, despite his many entreaties, to negotiate directly with the Taliban – a policy that Trump reversed. “It’s what State is good at, which is negotiations for deals,” Nasr said. “The military didn’t want it and wouldn’t allow it. They were hellbent on winning the war.”

Many who served in uniform in Afghanistan or led the campaign have mixed feelings about the past two decades and how the U.S. war is ending.

Retired Adm. Mike Mullen, chairman of the Joint Chiefs of Staff from 2007 to 2011, recalled that Afghanistan has long been known as the “graveyard of empires,” where the British in the 19th century, and the Soviet Union in the 20th, abruptly departed after long and largely pointless occupations.

“We just didn’t believe that,” he said. “We thought we could turn it, and obviously overestimated what we thought we could get done.” He cited persistent official corruption in Afghanistan amid a constant flow of U.S. money, and what he called the “fatal distraction” of the 2003 U.S. invasion of Iraq that consumed attention and troops.

While he remains concerned about the spread of global terrorism, Mullen said, “as far as Afghanistan is concerned, 20 years is more than enough.”