“Saigon.” Even those who weren’t alive to watch America’s ignominious exit from South Vietnam in 1975 can conjure the image: a helicopter perched atop an apartment building, loaded with evacuees, a photographic memorial for the country’s defeat and a sign of the wrenching political and cultural reckoning that was to come.

That scene is already being compared to the images of desperate Afghans running alongside a transport plane at Hamid Karzai International Airport, in Kabul, on Monday. Several clung to the plane, only to fall to their deaths once it took off.

As with the photographs from Saigon, it is hard not to see the airport scene as a portrait of American failure. The comparison also raises a question: Will the country’s two-decade debacle in Afghanistan come anywhere close to resembling Vietnam’s long-reaching effect on U.S. politics and culture?

To explore that question, I reached out to several historians who write about the 1970s and the end of the Vietnam War. While drawing historical parallels can be a fool’s errand, they agreed there are still lessons to be learned.

Jefferson Cowie, a historian at Vanderbilt University and the author of “Stayin’ Alive: The 1970s and the Last Days of the Working Class,” said that one consequence of the Vietnam War was a recognition of the limits of American power, a theme that ran like a red thread through the country’s politics and culture in the 1970s.

“There was a debate over limits of all kinds in the United States in the 1970s — to foreign policy, energy, growth and our standing in the world,” Professor Cowie said. But that debate had its own political consequences, giving rise, by the end of the decade, to a renewed belief in American power, driven by the Republican Party.

“The national debate ended with Ronald Reagan declaring that ‘we are too great a nation to limit ourselves to small dreams,’” Professor Cowie said. “Like the 19th century, there were no economic or geographic limits to the American power.”

He left open the question of whether America would see a similar rightward tilt in the coming years, though it’s not hard to imagine a Ron DeSantis or a Josh Hawley running a presidential campaign on a promise to yet again restore American greatness.

Mary L. Dudziak, a law professor at Emory University and the author of “War Time: An Idea, Its History, Its Consequences,” agreed that any attempt at reckoning would be short-lived, and that in the long term America could become even less constrained in its assertion of power.

“I expect that one similarity,” she said, “will be a failure to grapple with the way U.S. political culture undermines a more robust politics of military restraint, and this hampers powerful political opposition within Congress, which might put a brake on the entry into and persistence of war.”

What might have been a sustained, nuanced conversation about limiting the president’s war powers, she added, has been short-circuited by the frenzy to decide “who lost Afghanistan.”

“In our toxic political environment,” Professor Dudziak said, “Republicans are likely to use this moment to undermine President Biden, and partisanship may foreclose the deeper re-examination of American war politics that is sorely needed now, and was also after the war in Vietnam.”

What about the broader cultural implications? Philip Jenkins, a scholar of religious history at Baylor University and the author of “Decade of Nightmares: The End of the Sixties and the Making of Eighties America,” said he saw a similarity between then and now in the confluence of anti-establishment conspiracy-mongering and a sudden political disaster for the American government.

“Anti-government conspiracy theories had flourished from the late 1960s and reached amazing heights in the mid-late 1970s with all the assassination theories,” he said. What Vietnam did, he added, “was to take those ideas and transform them definitively into anti-government and anti-liberal directions.”

The collapse of faith in public institutions in the 1970s wasn’t just about Vietnam — Watergate, environmental crises and the general skepticism that the boomer generation held for its elders were all contributing factors. But Vietnam towered above them, not only because it touched so many people, but also because it brought into sharp focus the failure of the American government to do the thing it was supposedly best at: winning wars.

Today, of course, we are much more jaded, a fact that Professor Jenkins said might soften the impact of defeat.

“Vietnam was different, partly because it was a novel U.S. defeat, not something that people were used to back then,” he said. “American observers this time have almost come to expect that something like this will happen.”

Of course, the Biden administration is hoping that Professor Jenkins is right, at least in a narrow sense. “This is manifestly not Saigon,” Secretary of State Antony Blinken said over the weekend. Several historians agreed.

“Seeing Afghanis hoping to get out of their country with the U.S. troops leaving in the night is obviously reminiscent of those trying to escape the fall of Saigon,” Professor Cowie said, “except it’s not. Vietnam structured everything from politics, dissent, popular culture, elections, etc. In contrast, few cared or knew what was happening in Afghanistan or, for that matter, Iraq.”

Amanda C. Demmer of Virginia Tech, the author of “After Saigon’s Fall: Refugees and U.S.-Vietnamese Relations, 1975-2000,” said that such invisibility stemmed from two factors.

The first is obvious: While the United States fought the Vietnam War with millions of conscripts, the war in Afghanistan was fought by volunteers, and in much smaller numbers. That meant not only that fewer civilians knew anyone directly affected by the fighting, but also that the Afghanistan war had a much different moral valence — no one was being forced to fight.

Professor Demmer added a second point: What we know about Afghanistan, and how we know it, is vastly different from the experience with Vietnam.

“Americans received nearly identical coverage of the Vietnam War regardless of where they got their news,” she said, while “those who have retained their interest in Afghanistan (and have had to seek out information) have been able to select disparate portrayals to support their perspectives from echo chambers of coverage.”

In other words, the uniformity of the news media 50 years ago forced a national reckoning; the lack of a coherent narrative, let alone a coherent set of facts, around Afghanistan makes such a reckoning much less likely.

But that doesn’t mean the spectacle of a botched withdrawal won’t leave a scar.

David Paul Kuhn, the author of “The Hardhat Riot: Nixon, New York City, and the Dawn of the White Working-Class Revolution,” said he expected that the public had already turned inward after decades of war in Iraq and Afghanistan, and that the scenes in Kabul would reinforce Americans’ isolationism, seasoned with ever-greater partisan antagonism.

“Then, as now, America is a nation consumed by domestic disunion as we retreat from our longest war — and with that retreat, our footprint on the world stage recedes,” he said. “Thus, we are living Afghan-Iraq Syndrome, echoing the Vietnam Syndrome of old. The nation has turned inward, as it did then.”

Perhaps the most useful parallel between then and now is a more general point — namely, that military failures have a habit of illuminating all that is wrong in a society and its politics. In the 1970s, it was the sputtering end of an era built on the myth of American superiority. The urban and ecological crises at home, just like the military crisis in Southeast Asia, could not be solved no matter how much money or political will was expended.

The same is true today. As Mr. Kuhn pointed out, the fundamental inequity of the war — the small number of soldiers deployed, drawn from a small number of communities — reflects the vast inequities of modern American life.

“The 9/11 wars might come to capture their own class war, one truer to this era: the division between those on our front lines, and those on the sidelines,” he said. “From an American perspective, it is our small warrior class who mostly suffered this war. It is our ‘essential workers’ who disproportionately suffer this pandemic. Amid historic wealth and cultural gaps, is this once-iconic meritocracy increasingly dependent on a small worker class to do our suffering? Have we now become a society of ‘expendables?’”