Palmyra must not “rise again”, as Syria’s director of antiquities has promised. It must not be turned into a fake replica of its former glory. Instead, what remains of this ancient city after its destruction by Isis – and that is mercifully more than many people feared – should be tactfully, sensitively and honestly preserved.

The honesty has to begin with Palmyra’s newfound fame. Before Isis seized this extraordinary Syrian site last year, Palmyra was a name known best to archaeologists, historians and classicists. In a monstrous and horrific way, by blowing up some of its most beautiful monuments and carrying out inhuman atrocities amid its splendours, the terrorist army has made Palmyra known.

If Syria’s tragedy ever ends, if there is a peaceful Syria somewhere in the future, tourists will flock to a city now seen as a kind of Pompeii of the desert. And what will they find?

Ruins, of course. Palmyra was in ruins before Isis occupied it and it is still in ruins today. That is the nature of ancient cities. Mycenae, Machu Picchu, the Roman Forum – none are complete, none pristine. Their atmosphere and poetry lie in their scarring by time, nature and history.

Russian combat engineers check for mines in the retaken city. Photograph: Konstantin Leyfer/TASS

Palmyra had some remarkably well-preserved ancient buildings. The Temple of Bel stood poignantly as a survival of the city’s ancient religion. Only two columns and a lintel remain after it was blown up by Isis in August 2015. An arch dedicated to the Roman emperor Septimius Severus similarly withstood the centuries until it was brutally demolished last October. The Temple of Baalshamin has also been obliterated.

How can these terrible losses be put right? That seems to be the question archaeologists are asking. It seems to be what the world expects. Yet it may be the wrong approach. Restoration is a delicate art, and the responsible preservation of antiquities has to mean accepting the finality of loss where rebuilding might be deceitful.

The first job in Palmyra is to assess the damage very, very carefully. It will surely take many years to sift through the rubble of the demolished buildings with the appropriate caution and precision. If enough chunks of masonry and sculpture have survived in sufficiently recognisable shape, it may indeed be possible to re-erect parts of buildings or even entire structures. That would be wonderful. On the other hand, it may turn out to be more truthful to display the fragments in a specially constructed museum.

What is never legitimate is to rebuild ancient monuments using modern materials to replace lost parts – to essentially refabricate them – even though today’s technology makes that seem practical. I don’t see how anyone at this moment can vow to fully restore Palmyra unless they plan to ride roughshod over archaeological reality. The best anyone can say is that they will do the best that can be done.

The north entrance of Arthur Evans’s restoration of Knossos in Crete, complete with charging-bull fresco. Photograph: Doug Pearson/Getty Images/AWL Images RM

This Isis attack was not a counterfactual fantasy. It really occurred

In our age of digital scanning, satellite photography and 3D printing, it is tempting to succumb to the delusion that every ruin can be restored. Yet the hard lesson of three centuries of modern archaeology is that over-restoration damages the past. Pompeii was excavated by sensitive scholars who preserved its paintings without excessively touching them up, or “completing” the Roman houses. By contrast, the British archaeologist Arthur Evans created a strange mess in his arrogant over-restoration of Knossos in Crete.

It is always more moving to see the real stuff of the past, however damaged, than to see a faked-up approximation. The temptation to “fix” Palmyra and make it look like it did at the start of 2015 is understandable. This fascinating place has been subjected to a barbaric onslaught, the thinking goes. Surely it should be as if Isis never did their worst.

History is not like that. The Isis attack on Palmyra was not a counterfactual fantasy. It really occurred. This 21st-century tragedy is part of Palmyra’s history now. This too, for the sake of truth and as a warning to the future, must be preserved.