The last U.S. soldier to board a military plane out of Kabul on Tuesday was actually a general, Army Maj. Gen. Christopher T. Donahue, commander of the 82nd Airborne Division. He is seen in several widely circulated images taken in the final moments of the U.S. occupation, including one in which he strides up the ramp of a waiting C-17 military transport plane. He is rendered in the monochromatic green of a night-vision scope, a solitary figure, alone for a moment on hostile ground. Behind him, a few lights still shine at the Kabul airport, now controlled by the Taliban.

This is the end of a 20-year war. That’s the meaning ascribed to this powerful but deeply fraught image, which has the potential to do lasting damage if we can’t separate its truth from its mythological power.

The truth of the image, as far as we know it, is precise but limited. While he may have been wearing “the last boots on the ground” by the definition of some journalists and politicians, he was certainly not the last American with feet on the ground. Americans remain in Afghanistan, some willingly, others not, and we will almost certainly be back one way or another.

And while the American military evacuation is now over, other countries and many NGOs continue to operate in the country. Donahue’s departure initiates a new age of American military and diplomatic absence, but it closes the book on few things that are essential to the daily lives of Afghans.

Thus, the ghostly green picture symbolizes not the end of a war, but the end of a mission. But images are subject to “mission creep” — the almost inevitable expansion of purpose that dogs so many military ventures — and it is tempting to use this as an iconic bow to wrap up a long and tragic chapter of American and Afghan history. By accident or design, this representation is perfectly constructed to give a sense of cinematic finality. Although the palette is green, it renders the world in black-and-white, like films made a century ago. The round format — not obvious in many reproductions which crop it square — suggests the classic “iris” shot used by directors in the age of silent movies to end a scene, or a whole film.

The basic trope — the last man on the ground — recalls an emotionally resonant idea of responsibility and even chivalry. The captain is the last one off a sinking ship. The general is the last one out the door as the United States turns off the lights in Afghanistan. War, which is always messy, brutal and chaotic, is represented by a scene of individual valor, which is an important but limited truth.

The reduction of the war to a solitary figure who looks a little beleaguered animates multiple narratives, especially the idea that leadership is a lonely business. It also recalls a story line common within the military: Soldiers do their duty, often in service to incompetent or unscrupulous civilian leaders. In this case, a general serves as the dutiful, common soldier in an image that implicitly says: We played our role and did our duty. Defeat is a political matter, not a military one.

As wars are increasingly fought with drones, it is tempting to underscore and celebrate individual valor, not just because it is worthy but because it appeals to romanticized ideals of how wars were supposedly fought in a less technological age. When the president and military leaders talk of managing the terror threat from Afghanistan with “over the horizon” capabilities, they almost certainly mean more drones, more satellites, more video screens and more decisions made from rooms thousands of miles from the battlefield. The “last boots on the ground” message elides that truth, tempting us to believe that war is still a symmetrical contest among men, not a battle fought on one side with machines and money, and on the other with terror and zealotry.

A year after the United States went to war in Afghanistan, Andrew H. Card Jr., the White House chief of staff to George W. Bush, said: “From a marketing point of view, you don’t introduce new products in August.” By “new products” he meant the looming war in Iraq, which was sold to Americans as easily winnable, with little hint of the long, bloody struggle that would follow. War, as a product, is always sold with an implicit end date, an inevitable victory, a promise of finality. Since the age of silent films, perhaps only one U.S. war, the one fought against Germany and Japan, has actually ended that way, but still the product sells.

It takes more than collective amnesia or delusion to keep buying the promise. It requires an emotional investment in the basic narratives of heroism and duty so profound that it limits critical thinking about the purpose, objectives and consequences of war.

This image captures an admirable sense of duty, and conveys a compelling sense of closure. But it says nothing about the consequences of war, either for U.S. personnel killed, injured or emotionally scared by the events of the past 20 years, or for the millions of Afghans for whom this was an unwanted and often brutal visitation.