What is it about graven images? Why are we humanoids so prone to destroy our own faces, smash our own human history, erase the memory of language? I've covered the rape of Bosnian and Serb and Croatian culture in ex-Yugoslavia – the deliberate demolition of churches, libraries, graveyards, even the wonderful Ottoman Mostar Bridge – and I've heard the excuses. "There's no place for these old things," the Croat gunner reportedly said as he fired his artillery battery towards that graceful Ottoman arch over the Neretva. The videotape of its collapse was itself an image of cultural genocide – until the Taliban exploded the giant Buddhas of Bamian.

And yet there I was earlier this week, staring at another massive Buddha – this time in the Tajiki capital of Dushanbe, only a few hundred miles from the Afghan border. So gently was it sleeping, giant head on spread right hand, that I tiptoed down its almost 40ft length, talking in whispers in case I woke this creature with its Modigliani features, its firmly closed eyes and ski-slope nose. Saved from the ravages of iconoclasts, I thought, until I realised that this karma-inducing god had itself been assaulted.

The top of its head, eyes and nose are intact, but the lower half of its face has been subtly restored by a more modern hand, its long body, perhaps three-quarters new, where the undamaged left hand, palm on hip, lies gently on its upper left leg above the pleats of its original robes. So what happened to this Buddha? Surely the Taliban never reached Dushanbe.

A young curator at Dush-ambe's wonderful museum of antiquities explained in careful, bleak English. "When the Arabs came, they smashed all these things as idolatrous," she said. Ah yes, of course they did. The forces of Islam arrived in modern-day Tajikistan in around AD645 – the Taliban of their day, as bearded as their 20th-century successors, with no television sets to hang, but plenty of Buddhas to smash. How on earth did the Bamian Buddhas escape this original depredation?

The Buddhist temple at Vakhsh, east of Qurghonteppa was itself new (given a hundred years or two) when the Arabs arrived, and the museum contains the "work" of these idol-smashers in desperate, carefully preserved profusion. Buddha's throne appears to have been attacked with swords and the statue of Shiva and his wife Parvati (sixth to eighth centuries) has been so severely damaged by these ancient Talibans that only their feet and the sacred cow beneath them are left.

Originally discovered in 1969 30ft beneath the soil, the statue of "Buddha in Nirvana" was brought up to Dushanbe as a direct result of the destruction of the Buddhas in Afghanistan. Taliban excess, in other words, inspired post-Soviet preservation. If we can no longer gaze at the faces of those mighty deities in Bamian because the Department for the Suppression of Vice and Preservation of Virtue in Kabul deemed them worthy of annihilation, we can still look upon this divinity in the posture of the "sleeping lion" now that it has been freighted up to Dushanbe by the local inheritors of Stalin's monstrous empire. A sobering thought.

A certain B A Litvinsky was responsible for this first act of architectural mercy. Eventually the statue was brought to the Tajiki capital in 92 parts. Not that long ago, a fraternal Chinese delegation arrived and asked to take the sleeping Buddha home with them; they were told that they could only photograph this masterpiece – which may be the genesis of the "new" Buddha in the People's Republic.

Needless to say, there are many other fragments – animals, birds, demons – that made their way from the monastery to the museum. And I had to reflect that the Arabs behaved no worse than Henry VIII's lads when they set to work on the great abbeys of England. Did not even the little church of East Sutton above the Kentish Weald have a few graven images desecrated during the great age of English history? Are our cathedrals not filled with hacked faces, the remaining witness to our very own brand of Protestant Talibans?

Besides, the arrival of the Arabic script allowed a new Tajiki poetry to flourish – Ferdowsi was a Tajik and wrote Shanameh in Arabic – and in Dushanbe, you can see the most exquisite tomb-markers from the era of King Babar, Arabic verse carved with Koranic care into the smooth black surface of the stone. Yet when Stalin absorbed Tajikistan into the Soviet empire – cruelly handing the historic Tajiki cities of Tashkent and Samarkand to the new republic of Uzbekistan, just to keep ethnic hatreds alive – his commissars banned Arabic. All children would henceforth be taught Russian and, even if they were writing Tajiki, it must be in Cyrillic, not in Arabic.

Mustafa Kemal Ataturk was similarly "modernising" Turkey at this time by forcing Turks to move from Arabic to Latin script (which is one reason, I suspect, why modern Turkish scholars have such difficulty in studying vital Ottoman texts on the 1915 Armenian Holocaust). Get rid of the written language and history seems less dangerous. Didn't we try to do the same thing in Ireland, forcing the Catholic clergy to become hedge-preachers so that the Irish language would remain in spoken rather than written form?

And so the Tajiki couples and the children who come to look at their past in Dushanbe cannot read the Shahnameh as it was written – and cannot decipher the elegant Persian poetry carved on those extraordinary tomb-stones. So here is a tiny victory against iconoclasm, perhaps the first English translation of one of those ancient stones which few Tajiks can now understand:

"I heard that mighty Jamshed the King/ Carved on a stone near a spring of water these words:/ Many – like us – sat here by this spring/ And left this life in the blink of an eye./ We captured the whole world through our courage and strength,/ Yet could take nothing with us to our grave."

Beside that same East Sutton church in Kent, there still stands an English tombstone which I would read each time I panted past it in my Sutton Valence school running shorts on wintry Saturday afternoons. I don't remember whose body it immortalises, but I remember the carved verse above the name: "Remember me as you pass by,/ As you are now, so once was I./ As I am now, so you will be./ Remember Death will follow thee."

And I do recall, exhausted and frozen into my thin running clothes, that I came to hate this eternal message so much that sometimes I wanted to take a hammer and smash the whole bloody thing to pieces. Yes, somewhere in our dark hearts, perhaps we are all Talibans.