Shortly after then-Sen. Joe Biden in 2001 joined his colleagues in unanimously approving waging war in Afghanistan, he declared the effort required American boots on the ground and predicted the world would judge the U.S. harshly if it did not stay the course, allowing "the hope of a liberated Afghanistan to evaporate."
Twenty years later, President Biden defended his decision to withdraw from Afghanistan with the same level of confidence, portraying it as a moral imperative while forcefully rejecting criticism over the chaotic exit and new era of Taliban rule that saw millions of Afghans' hard-won freedoms vaporize virtually overnight. And upon completion of the withdrawal, Biden applauded the "extraordinary success of this mission."
But while Biden has stood ardently by his view, the Afghanistan withdrawal continues to cast a pall over his administration two years after the exodus. While the episode has become fodder for attacks from the president's critics, there are also signs the exit left a lasting mark on those within his administration, altering its approach to foreign policy in ways seen and unseen.
In an excerpt from an upcoming book, "The Last Politician: Inside Joe Biden's White House and the Struggle for America's Future," by Franklin Foer published in The Atlantic covering the dynamics inside the White House during the summer of 2021, Biden is depicted approaching the withdrawal with "determination, even stubbornness," as well as being "furious" over negative media coverage.
Retired Rear Adm. Mark Montgomery, now senior director of the Foundation for the Defense of Democracies' Center on Cyber and Technology Innovation, says what he called Biden's myopic approach resulted in the president shutting out critical warnings.
"In the face of significant pushback from the senior military advisers, he overrode all their concerns and recommendations, and executed an absolutely catastrophically bad policy," he argued in an interview with ABC News.
"He clearly has foreign policy bonafides. But with this president, there's a blind spot," Montgomery said, maintaining that attitude has now seeped through the ranks. "I do not believe that they are willing to have an open transparent discussion of what went wrong."
Daniel Byman, senior fellow with the Transnational Threats Project at the Center for Strategic and International Studies and a part-time senior adviser to the State Department, says many officials feel they have turned the page.
"I think that there's a limited focus on this at best within the Biden administration," he said. "It's not occupying the time of senior officials."
Their focus, Byman says, has turned to different areas they consider to be "major success," including the administration's support for Ukraine and approach to China, which many worry seems poised to invade Taiwan.
But for many Americans left behind in the chaotic withdrawal, it has taken months or even years to move on from Afghanistan.
Although Biden estimated at the end of August of 2021 that 100 to 200 American citizens who wanted to depart Afghanistan remained in the country, Secretary of State Antony Blinken indicated last month that the administration had facilitated the departure of roughly 900 U.S. citizens since the U.S. occupation ended.
"I believe some 900 or so additional American citizens who’ve told us at one point or another that they wanted to leave we’ve made sure could get home," he said at a press availability.
But an unknown number of Americans are still trapped, including some who are being detained by the Taliban. Thousands of Afghan allies eligible for resettlement in the U.S. are also still awaiting relocation.
On the world stage, Montgomery says the perception of calamity in Afghanistan has amplified the need for the United States to succeed in other theaters.
"You really could see us as a very dubious ally," he said. "If you're Taiwan, if you're Japan or Korea, if you're Estonia, Latvia, Lithuania, you have to be asking yourselves is the United States willing to sacrifice American service members to meet its treaty or stated obligations to us?"
By backing Ukraine, Montgomery says the administration has restored some of its standing in the eyes of the world, but not all -- especially when it comes to deterring adversaries from inciting conflicts.
"The credible belief that the U.S. would commit military personnel does deter China. And one has to call into question the credibility if that based on the last two administrations," he said. "In the end, we're not willing to put U.S. troops where our rhetoric is."
On both Capitol Hill and the campaign trail, Republicans have maintained a steady drumbeat of reproval over Biden's handling of Afghanistan, launching inquiries and demanding accountability for what they argue were preventable failures.
Tuesday marked the first time several Gold Star family members of the 13 service members killed in the 2021 Abbey Gate bombing at Kabul's airport gathered on Capitol Hill to voice their frustrations, repeatedly calling for transparency from the Biden administration and accountability for decision-makers they say failed their children.
"I say to [Biden]: Resign," said Darin Hoover, father of Marine Staff Sgt. Darin Taylor Hoover.
"We deserve to know the truth and why the government sent our kids to their deaths," Coral Briseno, mother of Marine Cpl. Humberto Sanchez, added.
Joint Chiefs Chairman Mark Milley submitted a statement that was read aloud at the start of the hearing, saying of the Gold Star families, "We owe them transparency. We owe them honesty, we owe them accountability if appropriate. We owe them the truth about what happened to their loved ones."
"We don't like what happened in Afghanistan. We don't like the outcome of Afghanistan. We owe it to the families to take care of them," his statement said.
Also present was Marine Sgt. Tyler Vargas-Andrews, who testified before the House Foreign Affairs Committee in March that he believes his sniper team had the suicide bomber in its sights before the explosion but was not allowed by commanders to take the shot.
"This tragedy was a self-inflicted wound that not only killed 13 U.S. service members, but also killed 170 innocent civilians and injured 45 people in a massive suicide bombing attack," House Foreign Affairs Committee Chairman Michael McCaul, R-Texas, said at Tuesday's roundtable. "Simply put, it was hell on Earth, and the saddest part is it all could've been prevented."
But the Pentagon disputed McCaul's claim.
"From the investigation at the tactical level, the Abbey Gate attack was not preventable without degrading the mission to maximize the number of evacuees, and the leaders on the ground followed the proper measures and procedures," the Pentagon said in a statement Tuesday.
The day after the roundtable, the Gold Star families traveled north to Bedminster, New Jersey, where former President Donald Trump, who first laid plans for the departure of U.S. troops when he struck a conditional withdrawal agreement with the Taliban, hosted a dinner discussion Wednesday night.
In a message posted to social media about the meeting, Republican Rep. Mike Waltz said that Trump promised his guests that if he were elected again, he would "release everything" about the attack.
GOP presidential candidates have repeatedly dinged Biden over Afghanistan, with Sen. Tim Scott saying that what he called the "botched withdrawal" was "a tragedy for our nation" and former U.N Ambassador Nikki Haley saying "heads should roll" over the "Afghanistan catastrophe at Abbey Gate."
For many, the Biden administration's attempts at transparency have fallen flat.
In April, the White House issued a 12-page summary of its report on the "decisions and challenges" surrounding the withdrawal just ahead of the Easter weekend. It was widely interpreted as defensive -- a list of arguments aiming to shift blame more squarely onto the previous administration rather than provide genuine takeaways from the ordeal.
Then, on the cusp of another holiday -- the Friday before July Fourth -- the State Department released a public version of its own long-awaited After-Action Review on Afghanistan. The findings were more substantial and ascribed fault to both Biden and Trump, saying both men made decisions that had "serious consequences for the viability of the Afghan government and its security."
Still, critics accused the administration of once again trying to bury the information, and even some officials within the administration privately questioned the strategy behind the rollout and expressed frustration over the delay.
Montgomery says he doubts there's a real appetite to learn from experience because "the president thinks he did nothing wrong."
"There's no question this is not a story the administration wants a lot of attention on, so the fact that they're trying to bury it is not at all surprising to me," said Byman.
But both Byman and Montgomery predict attack lines on the withdrawal ultimately won't land with voters, primarily because Biden appears to have kept at least one core promise: so far, Afghanistan has not become a safe haven for terrorists again.
"Public attention is gone. It doesn't show up in polling as a major concern," he said.
Whether the Taliban will once again allow Afghanistan to become an incubator for extremism is still an open question.
Even though al-Qaeda has been subdued, other groups aligned with the Taliban -- including Tehreek-e-Taliban Pakistan (TTP), which is believed to have thousands of fighters across the eastern reach of the country -- have been expanding and escalating their operations, a report from the United States Institute of Peace published earlier this month found.
Biden has said he was right that the U.S. would "get help from the Taliban" on fighting terror, but Byman and Montgomery say the U.S. and the international community have little leverage over the de facto rulers' behavior.
"The Taliban have always made it clear that the economic prosperity of Afghanistan, the day-to-day well-being of their citizens is not their top priority," Byman said. "So there are going to be limits to how much economic assistance and recognition can do, but the hope is that you'll have some impact and trying to minimize the worst."
Still, Byman says there's some hope the Taliban "may be more cautious" on the extremism front than the group was during its previous rule, and that the U.S. can take action against threats.
"The U.S. does have some strike capability -- not nearly as much as it did two years ago," he said.
Montgomery is less optimistic, saying the administration has only been willing to take aim at the highest value targets within Afghanistan.
"The base of non-state actors to who want to damage the United States -- they're invariably going to grow inside Afghanistan," he said. "We could be facing a challenge like we did 20 years ago."
ABC News' Carly Roman contributed to this report.