After American troops departed Afghanistan, Gen. Frank McKenzie, the chief of the U.S. Central Command, said: “There’s a lot of heartbreak associated with this departure. We did not get everybody out that we wanted to get out. But I think if we’d stayed another 10 days, we wouldn’t have gotten everybody out that we wanted to get out.”

“Heartbreak” is the right word. So is “betrayal.”

Several hundred Americans and tens of thousands of Afghans — who loyally served the U.S. mission over the last two decades — have been left behind. As a nation, we’ve broken our promise to keep them and their families safe from the Taliban’s holy warriors who now occupy their country and seek revenge.

“This is a moral disaster,” proclaims a Washington Post editorial, “one attributable not to the actions of military and diplomatic personnel in Kabul — who have been courageous and professional in the face of deadly dangers — but to mistakes, strategic and tactical, by Mr. Biden and his administration.”

Perhaps keeping American troops in place for 10 more days would not have made a big difference, although that’s debatable. European leaders like British Prime Minister Boris Johnson strongly urged Biden to extend the U.S. military presence, and a recent ABC/Ipsos poll found large majorities of Americans favoring that course.

But the real mistakes that led to the current disaster were made many months ago, when the White House was warned — repeatedly and urgently — to speed up the process of granting Special Immigrant Visas (SIVs) to Afghan allies and employees. But the administration, which clearly wanted to believe that Afghan forces would be far more effective in resisting the Taliban than they proved to be, ignored the alarms.

As I wrote earlier this summer, after Biden pledged to protect our Afghan comrades: “But words are the easy part. At least so far, the administration seems uncertain and unprepared in dealing with those Afghan allies. The jeopardy they face was totally predictable, once Biden decided to pull out. So why isn’t there a better plan — any plan, really — in place already?”

The core of the problem is that Biden has followed two contradictory policy goals: Get our allies out AND get our troops out. Keep our promises AND keep to the Aug. 31 deadline. It was never going to be possible to fulfill both aims. That’s why he’s in such a mess. In his defiant and defensive speech from the White House, the president insisted “we were ready” for any eventuality, including the collapse of Afghan resistance to the Taliban, but that’s obviously not true.

He also said it was “time to be honest with the American people.” But he has never been honest about how and why he and his advisers made such a disastrous miscalculation about the fragility of the Afghan military — a miscalculation that has imperiled so many of our loyal Afghan allies.

So what happens now? The president talks a good game, saying there is “no deadline” on continuing efforts to extract vulnerable Afghans. But as Secretary of State Tony Blinken has admitted, “We have no illusion that any of this will be easy. Or rapid.”

With no U.S. soldiers, or even diplomats, left in the country, Washington must rely on allies like Turkey and Qatar to reopen the Kabul airport and enable evacuation flights to resume. “We’re also working to identify ways to support Americans, legal permanent residents and Afghans who have worked with us to depart via land routes,” Blinken adds.

The president continues to insist that the U.S retains enough “leverage” over the Taliban to make these strategies work, but it’s not at all clear what he means. Diplomatic pressure? Foreign aid? World opinion? And to believe promises from the Taliban is to indulge in the same wishful thinking and self-delusion that led to the current chaos.

As the Post wrote, “Any ‘assurances’ by the Taliban clash with statements their spokesmen made during the crisis that the United States was wrongly inducing Afghans to leave — not to mention the group’s record of murdering perceived enemies.”

Yes, the administration successfully extricated over 120,000 people from Afghanistan in recent weeks, a truly remarkable accomplishment, And foreign policy seldom becomes a voting issue in American elections.

But so far, Biden has failed to keep his word to many endangered Afghans who remain under Taliban tyranny.

“We’re far from done,” he vowed, and he must try everything possible in the weeks and months ahead to redeem that promise. His reputation, and the nation’s honor, depend on it.

Steven Roberts teaches politics and journalism at George Washington University. He can be contacted by email at stevecokie@gmail.com.