He [Biden] wanted all American troops out of Afghanistan by Sept. 11, the 20th anniversary of the attacks on New York and the Pentagon.
In the Oval Office, Defense Secretary Lloyd J. Austin III and Gen. Mark A. Milley, the chairman of the Joint Chiefs of Staff, wanted to make certain. “I take what you said as a decision, sir,” General Milley said, according to officials with knowledge of the meeting. “Is that correct, Mr. President?”
It was.
NYT
There would be no conditions put on the withdrawal, Mr. Biden told the men, cutting off the last thread — one that had worked with Mr. Trump — and that Mr. Austin and General Milley hoped could stave off a full drawdown….
They were told, Zero meant zero.
Yes, he [Biden] had joined 97 other senators on Sept. 14, 2001, to vote in favor of going to war in Afghanistan. He had even been in favor of the Iraq war the next year. …
The Defense Department had fended off an effort by Mr. Trump to abruptly pull out all remaining U.S. troops by last Christmas. Mr. Trump eventually ordered the force cut roughly in half — to 2,500, the smallest presence in Afghanistan envisioned by American counterterrorism planners, from 4,500. …
The Pentagon effort received another setback when Mr. Biden’s new director of national intelligence, Avril D. Haines, conveyed intelligence assessments that the nexus of terrorism had shifted from Afghanistan to Africa and other havens. That raised the question: Was the United States massing its forces for a 2001 threat or a 2021 threat? …
“But now that the decision has been made, I call upon them to lead their forces through this effort, through this transition,” Mr. Austin said. “And knowing them all very well, as I do, I have every confidence that they will in fact lead their forces through this effort.” …
But the rest — nation-building, democratization, establishing an effective internal security force, defending the rights of women and minorities — may have been a step beyond any military’s capabilities.
NYT