Enter Mr. Biden. To my shock, he embraced Mr. Trump’s Afghanistan policy. We have betrayed our promises to interpreters, women and children, and others who are now trapped in an Afghanistan controlled by the Taliban. I fear many will lose their lives because of Mr. Biden’s impatience. We had their backs. Until Mr. Biden decided we didn’t. They will pay for it.

It did not have to be this way. When I left Afghanistan as ambassador in 2012, we had about 85,000 troops in the country. The Taliban controlled none of Afghanistan’s 34 provincial capitals. When President Barack Obama left office there were fewer than 10,000 U.S. troops. And when Mr. Trump departed there were fewer than 5,000. The Taliban still did not hold any major urban area. Now, they hold the entire country. What changed so swiftly and completely? We did. Mr. Biden’s decision to withdraw all U.S. forces destroyed an affordable status quo that could have lasted indefinitely at a minimum cost in blood and treasure. Even with a full withdrawal, we might have managed steps that would have protected our interests. The ranking member of the House Foreign Affairs Committee, Michael McCaul, and I suggested how in these pages a few months ago.

Now, the Taliban hold all the cards. They will determine whether evacuations through the Kabul airport can proceed. And whatever happens next, the image of this American capitulation is already etched indelibly in the world’s imagination. It is that U.S. Air Force C-17 taxiing for takeoff from Kabul surrounded by a desperate Afghan mob. Seconds later, at least one man falls to his death from the plane’s wheel well. It is eerily reminiscent of the people who jumped from the World Trade Center on 9/11 rather than face death by fire. What a tragic and painful circle it closes two decades later.