The Taliban's lightning seizureof Afghanistan's capital yesterday exposed stunning failures of American intelligence, imagination and execution that will be studied as long as people study history.

The big picture: The United States was literally run out of town after 20 years, $1 trillion and 2,448 service members' lives lost.

• Mohammad Naeem, the spokesman for the Taliban's political office, toldAl Jazeera TV today: "Thanks to God, the war is over in the country."

Why it matters: A friend who spent more than a decade as a U.S. official in Afghanistan and Iraq texted me that the collapse "shows we missed something fundamental — something systemic in our intel, military and diplomatic service over the decades — deeper than a single (horrible) decision."

• As the BBC's Jon Sopel put it: "America's attempt to export liberal democracy to Afghanistan is well and truly over. America's effort to build a civil society in Kabul and beyond — also in tatters."

Zoom out: The Taliban triumph "sparked global alarm, reviving doubts about the credibility of U.S. foreign policy promises and drawing harsh criticisms even from some of the United States' closest allies," The Washington Post's Liz Sly reported from London.

• "[C]oncerns grew that the unfolding chaos could create a haven for terrorists, unleash a major humanitarian disaster and trigger a new refugee exodus."

🚁 President Biden got, as The New York Times' David E. Sanger notes in a front-page story, the "Images of Defeat He Wanted to Avoid."

• Secretary of State Tony Blinken, rejecting comparisons to America's helicopter airlift out of the Vietnamese capital in 1975, said on ABC: "This is manifestly not Saigon." And on CNN: "Remember, this is not Saigon."
• But Kimberley Motley, an international human-rights attorney who has worked on Afghanistan issues for 13 years and was desperately trying to help Afghans get out of the country, told The Wall Street Journal: "This is like Saigon on steroids."

Here's how the day unfolded in AP bulletins:

1. 1:56 a.m. ET: Helicopters land near U.S. embassy in Kabul as diplomatic vehicles leave compound amid Taliban advance.
2. 3:07 a.m.: Officials say Taliban now hold all of Afghanistan's border crossings, leaving Kabul airport as only route out.
3. 3:40 a.m.: Afghan officials say Taliban militants have entered outskirts of Kabul.
4. 4:04 a.m.: Taliban say in a statement they don't plan to take Kabul "by force," as sporadic gunfire echoes in Afghan capital.
5. 6:09 a.m.: Troops surrender Bagram Air Base, the Grand Central of America's 20 years in Afghanistan, to the Taliban.
6. 9:54 a.m.: Afghan officials say President Ashraf Ghani has left his country.
7. 11:54 a.m.: Acting U.S. ambassador is evacuated by military from the embassy to Kabul airport.
8. 12:15 p.m.: U.S. embassy tells Americans to shelter in place, says airport reportedly taking fire.
9. 1:54 p.m.: U.S. military officials say Kabul airport closed to commercial flights as military evacuations continue.
10. 2:43 p.m.: Al-Jazeera airs live footage of Taliban fighters in Afghan presidential palace.

Behind the scenes: The White House held separate bipartisan, unclassified briefing calls for the House and Senate, with Secretary of State Tony Blinken (after he did three Sunday shows), Defense Secretary Lloyd Austin and Chairman of the Joint Chiefs of Staff Mark Milley.

• Sources tell Jonathan Swan it was surreal: Senators were getting briefed by administration officials — while looking at their phones and seeing real-time chaos unfolding in Kabul.