This 9/11, all that is left is the grief.

For years, we thought the terror attacks of September 11, 2001, were not only a terrible event, but also a call to action, heralding a new vigilance at home and a new era of American leadership abroad.

Today, the U.S. has left the impression of scalding defeat in Afghanistan, our southern border is open to anyone who wants to cross it, and our leaders agree with our enemies that we are a morally corrupt society, deserving of being overthrown and replaced.

This week, as news outlets replayed the clips of President George W. Bush telling firefighters and rescue workers at Ground Zero that “the people who knocked these buildings down will hear all of us soon,” I had to wonder: could we muster that strength, as a nation, today?

Today, we have President Joe Biden’s administration praising the Taliban, the accomplices of 9/11, as “businesslike and professional,” after groveling for the release of American citizens Biden let behind.

This is the world the American left wanted.

The American left never knew what to do with 9/11. There was genuine shock and horror, but also a seething frustration that people would now forget the perceived injustice of the 2000 recount, that the public would rally around the flag, rather than rallying around political change.

Many believed fervently that the United States was fundamentally flawed, and they grumbled that the country, under attack, would only commit further injustices.

That view was reflected in international elite opinion.

I was living abroad in South Africa the time, and what shocked me most, aside from the horror of the attacks, was the fact that much of the country’s political elite quietly celebrated the event.

My Muslim neighbors came over to share their sorrow and sympathy, but the country’s opinion columnists said America got exactly what it deserved — never mind the fact that New York is the nation’s most cosmopolitan city, and that the victims were from dozens of countries.

No one could say exactly why America deserved to be attacked. America was simply too brash, too bold, too independent.

Not everyone agreed: former President Nelson Mandela visited New York to offer support, even standing together with President George W. Bush. But he was excoriated for it in ruling party circles, and he later turned on Bush.

Local newspapers painted the impending war against the Taliban in Afghanistan as if it were a crime against humanity. Then the Taliban fell, and the Afghan population celebrated, at least in Kabul.

The U.S., NATO, and the United Nations set about trying to build a functioning government, one that would not become a failed state that harbored terrorists, but would offer Afghans — especially women — a chance at a better life.

This was American leadership making a positive difference. The exercise in “nation-building” was not some utopian vision of Jeffersonian democracy; it was a strategic calculations that a country with real institutions would be safer for the world.

But the new Afghan ruling cliques, knowing how important they were to that strategy, exploited American taxpayers and the rest of the world, stealing billions of dollars while doing little to help their country, creating conditions ripe for the Taliban to re-emerge.

Still, failure was not inevitable until President Barack Obama, trying to placate the anti-war wing of the party from whence he came, announced in 2009 that his “surge” had an end date, meaning all the terrorists had to do was wait.

The failed conduct of the Iraq War was also crucial to the Afghanistan failure. The insurgency that arose after Bush toppled Saddam Hussein led to thousands of American deaths, while Iran, no longer checked by its rival, expanded its malevolent regional influence.

Bush eventually beat back the insurgency — though Obama later squandered those gains, and went on to repeat Bush’s mistakes in Libya. Yet rising anti-war sentiment, in both parties, doomed the U.S. mission in Afghanistan.

Democrats have labored mightily to rewrite the history of America’s involvement in Afghanistan as if Donald Trump were to blame for President Joe Biden’s disastrous withdrawal.

It is true that Trump continued Obama’s policy of moving toward a pullout, and has only belatedly discovered the strategic importance of a country that shares land borders with both China and Iran. But Obama was the first to negotiate with the Taliban — and badly, swapping five Taliban leaders for a deserter.

Four of those five are now senior members of the Taliban-led government announced this week. Another minister is on the FBI’s Most Wanted list, a terrorist with a bounty of millions on his head.

Trump pounded the Taliban mercilessly, and also pulled out of talks whenever an American was harmed. Under Trump, the U.S. was moving toward a withdrawal that the American people arguably had voted for, but was doing so in a way that preserved at least the impression of U.S. strength.

The catastrophic way in which Biden pulled out — leaving hundreds of Americans stranded, giving up $85 billion in arms to the Taliban, ignoring our NATO allies, and placing American servicemembers needlessly in harm’s way — created a clear impression of defeat.

That impression will last generations, and will have real consequences for our national security. It will convince our enemies that all they need to do is fight long enough and hard enough, and the Americans will succumb.

I cannot stop thinking of the Jewish holiday of Chanukah, which commemorates a miracle that took place in the Holy Temple after a group of religious Jewish zealouts had just retaken ancient Israel from a larger and more powerful Greek occupying military force.

Jews have praised God for more than 2,000 years for delivering “the mighty into the hands of the weak.” Why would the Taliban not draw similar inspiration from recent events — and for evil, rather than good?

Just as Afghanistan will inspire Islamists, it will haunt Americans.

Those of us who grew up after the Vietnam War were taught it was a failure of Cold War hubris. The Afghanistan War was seen, in contrast, as a righteous mission.

A defeat in a war of hubris can become a lesson for the future. A defeat in a just war is a crushing moral blow — and perhaps a fatal one to American self-confidence, delivered as our leaders lecture us about the evils of our society, just as the left once dreamed.

9/11 was, until now, tinged with hope that its sacrifices would not have been in vain.

This year, there is only grief. And deep worry about how, and whether, we can regain what we have lost.

Joel B. Pollak is Senior Editor-at-Large at Breitbart News and the host of Breitbart News Sunday on Sirius XM Patriot on Sunday evenings from 7 p.m. to 10 p.m. ET (4 p.m. to 7 p.m. PT). He is the author of the recent e-book, Neither Free nor Fair: The 2020 U.S. Presidential Election. His recent book, RED NOVEMBER, tells the story of the 2020 Democratic presidential primary from a conservative perspective. He is a winner of the 2018 Robert Novak Journalism Alumni Fellowship. Follow him on Twitter at @joelpollak.