NARRATION: Two decades after invading Afghanistan, the United States is withdrawing, leaving chaos in its wake and the country much as it found it twenty years ago.

ARCHIVAL (NBC, 8-16-21):NEWS REPORT: The Taliban dont just control Kabul, they control the whole country.

NARRATION: How did a war that began in response to the 9/11 attacks become the longest in American history?

MICHAEL MORELL: If somebody had told me in 2001 that we were going to be there for another 20 years, I would not have believed them.

NARRATION: And what lessons can be learned for the future?

TIMOTHY KUDO: We were doing the same thing year after year after year expecting a different result.

ARCHIVAL (MSNBC, 4-14-21):NEWS REPORT: Nearly 2,400 Americans have died in Afghanistan.

ARCHIVAL (MSNBC, 4-17-21):NEWS REPORT: More than 43,000 Afghan civilians lost their lives.

RICHARD BOUCHER: You cant remake a country on the American image. You cant win when youre fighting people for their own villages and their own territory. Those were lessons we thought we learned in Vietnam. And yet, 30 or 40 years later we end up in Afghanistan repeating the same mistakes.

NARRATION: On the morning of September 11th, 2001, President George W. Bush was visiting an elementary school in Sarasota, Florida, when he received word of an attack on the World Trade Center in New York City.

ARCHIVAL (FOX, 9-11-01):ANCHOR: Were looking at a live picture of the, of the building right now. And what would you say? We have a view of the 90th floor, or so?

NARRATION: The president joined his staff in an empty classroom, where his C.I.A. intelligence briefer, Michael Morell, had been watching the attack unfold

MICHAEL MORELL: There was a TV there and the second plane hit.

ARCHIVAL (FOX, 9-11-01):ANCHOR: Oh my goodness. Oh God. Theres another one. Oh. Oh my goodness, theres another one. God.

MICHAEL MORELL (FORMER ACTING DIRECTOR, CENTRAL INTELLIGENCE AGENCY): And when that happened, um, I knew that this was an act of terrorism.

NARRATION: At the Capitol in Washington, Representative Barbara Lees meeting was interrupted.

BARBARA LEE (DEMOCRAT-CALIFORNIA): I heard a lot of noise saying evacuate. Leave. Get out of here. Run fast. So, I ran up Independence Avenue. As I turned around, I was able to see a heck of a lot of smoke.

ARCHIVAL (FOX, 9-11-01):ANCHOR: Another aircraft, unbelievably, has crashed into the Pentagon.

MICHAEL MORELL: What you have to understand is this is the largest attack ever in the entire history of the country.

NARRATION: At 9:59 a.m., the second World Trade Center tower to be struck collapsed. Twenty-nine minutes later, the other tower followed.

MICHAEL MORELL: The President, he asked to see me in his office on Air Force One. The President looked me in the eye and he said, Michael, who did this? I told the President that I would bet my childrens future that Al Qaeda was responsible for this attack.

NARRATION: Within hours, evidence surfaced that Al Qaeda, a multinational terrorist organization headed by the Islamic fundamentalist Osama Bin Laden, had committed the attacks. The group was being given safe haven in Afghanistan by the Taliban regime.

MICHAEL MORELL: The Presidents inclination was to hit back and hit back hard.

ARCHIVAL (9-14-01):PRESIDENT GEORGE W. BUSH: I can hear you! The rest of the world hears you. And the people

MICHAEL MORELL: So, the President decided to, to go to war.

ARCHIVAL (9-14-01):PRESIDENT GEORGE W. BUSH: And the people who knocked these buildings down will hear all of us soon.

RICHARD BOUCHER (FORMER ASSISTANT SECRETARY OF STATE): We had to go to Afghanistan, theres no question in any of our minds, its a war of necessity. We had to go after Al Qaeda, we had to kill them, we had to get them out and we had to pursue them to the ends of the Earth.

BARBARA LEE: The word on the street was everyones got to be united with the President. You know, the country is in mourning.

NARRATION: Three days after the attacks, Lee was under pressure to vote yes on a resolution in Congress to authorize going to war against Al Qaeda and its allies when she heard a eulogy at a memorial service.

ARCHIVAL (ABC NEWS, 9-14-01):REVEREND NATHAN BAXTER: That as we act, we not become the evil we deplore.

BARBARA LEE: It was at that point I said, We need to think through our military response, our national security response, and the possible impact on civilians.

ARCHIVAL (C-SPAN, 9-14-01):BARBARA LEE: Mr speaker, members, I rise today really with a very heavy heart. One that is filled with sorrow for the families and the loved ones who were killed and injured this week. Yet I am convinced that military action will not prevent further acts of international terrorism against the United States.

BARBARA LEE: Got back to the office and all hell was breaking loose.

ARCHIVAL (CNN, 9-14-01):NEWS REPORT: The only dissenting voice was Democrat Barbara Lee of California, voting no.

BARBARA LEE: Phone calls, threats. People were calling me a traitor. Shes got to go. But I knew then that it was going to set the stage for perpetual war.

NARRATION: Within weeks of 9/11, the U.S. struck back in Afghanistan.

ARCHIVAL (REUTERS, 10-9-01):PRESIDENT GEORGE W. BUSH: The United States military has begun strikes against Al Qaeda terrorist training camps and military installations of the Taliban regime.

NARRATION: Soon after, U.S. ground troops arrived in the country.

RICHARD BOUCHER: The invasion was a success very quickly.

ARCHIVAL (CNN, 11-13-01):NEWS REPORT: At the gates of Kabul, news of a Taliban collapse had already reached these thousands.

ARCHIVAL (CBS, 11-13-01):NEWS REPORT: The Taliban retreat has turned into a rout.

MICHAEL MORELL: By the end of the year, the Taliban had been driven from power, a large number of Al Qaeda operatives had either been killed or captured.

NARRATION: And although Osama Bin Laden had managed to escape, the U.S. had accomplished its main goal.

MICHAEL MORELL: Al Qaeda could not operate out of Afghanistan anymore.

NARRATION: President Bush knew there was a history of failed military campaigns in Afghanistan.

ARCHIVAL (C-SPAN, 4-17-02):PRESIDENT GEORGE W. BUSH: We know this not only from intelligence from the history of military conflict in Afghanistan. Its been one of initial success followed by long years of floundering and ultimate failure. Were not going to repeat that mistake.

NARRATION: But after his initial success, Bush expanded the mission to nation-building. To prevent further Al Qaeda attacks, his administration said it wanted to transform the poor, war-torn country into a stable democracy, with a strong central government and U.S.-trained military.

MICHAEL MORELL: The idea was it would be impossible for the Taliban to ever return to power and impossible for Afghanistan to ever be used as a safe haven again.

RICHARD BOUCHER: There were girls starting to go to school, there were clinics and hospitals being set up, there were vaccinations, there were elections planned. Everything was kinda humming along and we all thought, Okay, this is gonna be fine.

NARRATION: But by the mid-2000s, after the Bush Administration expanded the war on terror to Iraq, Richard Boucher realized that the U.S.-backed Afghan government was plagued by corruption and mismanagement.

RICHARD BOUCHER: I used to say to my guys on the Afghan desk, If were winning, how come it dont look like were winning?

ARCHIVAL (ABC, 9-8-06):NEWS REPORT: The Taliban have staged a major comeback, seizing control of large swaths of the country.

RICHARD BOUCHER: The people were not rejecting the Taliban. That was, in the end, because the government couldnt deliver much for the people. Everybody had this idea in their heads that government works the way it does in Washington. But Afghanistan hasnt worked that way in the past. I think that was a moment, we shouldve at least asked ourselves whether it wasnt really time for us to leave and to say to the Afghans, Its your place, you run it as best you can.

NARRATION: Instead, by 2011, President Bushs successor, Barack Obama, had sent nearly 50,000 more troops to Afghanistan, hoping to reverse the Talibans gains.

ARCHIVAL (ABC, 7-20-08):PRESIDENT BARACK OBAMA: I think one of the biggest mistakes we made strategically, after 9/11, was to fail to finish the job here, focus our attention here. We got distracted by Iraq.

NARRATION: One of those troops was Marine captain Timothy Kudo. Part of his job was to shore up support for the government by digging wells and building schools. He soon lost faith in that mission after, he says, his company killed two Afghan teenagers they mistakenly believed were firing on them.

TIMOTHY KUDO (FORMER MARINE CAPTAIN): And their family saw this happen. The mothers, the grandmothers, they came out. It was the first time Id ever seen an Afghan woman without wearing a burqa. They were sobbing and crying uncontrollably. I mean, how can you kill two innocent people and expect anything that you say to matter at that point?

ARCHIVAL (ABC, 2-9-09):NEWS REPORT: People here have little faith in U.S. forces anymore. More Afghans blame the violence here on the U.S. than on the Taliban.

NARRATION: Weeks after Kudo returned home from Afghanistan, there was a monumental development.

TIMOTHY KUDO: I started getting all these texts, like, Youve got to check out the TV. My roommate calls me to the room. Turn on CNN.

ARCHIVAL (5-2-11):PRESIDENT BARACK OBAMA: The United States has conducted an operation that killed Osama Bin Laden, the leader of Al Qaeda.

TIMOTHY KUDO: In that moment, people are celebrating in front of the White House. Theyre celebrating right at Ground Zero.

ARCHIVAL (ASSOCIATED PRESS, 5-2-11):CROWD: This is where it happened. Were back. Justice!

TIMOTHY KUDO: And to my mind, theres no more reason to go through this madness. And, of course, we then did it for another decade.

MICHAEL MORELL: I think the military and the national security apparatus thought they could win. And I think that they also wanted to believe that because they had invested so much. People had died and they didnt want them to die in vain.


NARRATION: Jeffrey Eggers was on President Obamas National Security Council. He says that the goal, since 9/11, to make sure Afghanistan would never again be a safe haven for terrorists had become a recipe for endless war.

JEFFREY EGGERS: We will forever prevent the conditions that led to such an attack.


JEFFREY EGGERS: And if you define it that way, when are you finished?


NARRATION: Though the surge failed to push back the Taliban, the U.S. drew down troop levels even as doubts were growing that the Afghan forces would be able to defend the country. In 2021, President Biden, the fourth president to preside over the war, announced that he would withdraw U.S. troops, a plan set in motion by his predecessor, Donald Trump.

MICHAEL MORELL: Nobody should have any doubts; we lost the war in Afghanistan. It wasnt a peace agreement; it was a withdrawal agreement. The agreement was essentially As we withdraw, dont attack us.

NARRATION: As the U.S. leaves Afghanistan, the Taliban is taking over again, having quickly overrun the Afghan army, which the U.S. spent more than $80 billion to train and equip.

ARCHIVAL (NBC, 8-16-21):NEWS REPORT: The Taliban are out in full force. And their Islamist rule is already coming back.

ARCHIVAL (NBC, 8-15-21):NEWS REPORT: They can use this as a recruiting tool. They are now the champions of the jihadi movement because they pushed out the United States.

NARRATION: And U.S. officials are reflecting on the beginning of the war, twenty years after 9/11.

RICHARD BOUCHER: More people should have thought about endless war, not just in Congress but in the State Department, in Defense Department, CIA and elsewhere, in the White House. That the recipe of using military means to go after terrorism was just gonna get us into one fight after another after another. One can only hope that Americans of the new generation will think about this.