FEW forms of conflict are so damaging to a country as a prolonged civil war. By 1939, when Franco’s forces had finished mopping up the last Republican resistance in Spain, more than half a million lay dead and some of the most beautiful city centres in Europe had been destroyed.

A similar pattern played out in 1970s Lebanon, which saw 150,000 casualties and the almost complete destruction of the elegant villas of Ottoman Beirut. In Afghanistan it was not Soviet invasion or occupation that killed most people or wrecked Kabul, but the internecine fighting that followed in the early 1990s.

As Masood’s rockets fell on the Pakhtun neighbourhoods of Kabul, and Hekmatyar’s forces emptied the Tajik suburbs, palaces and museums were looted.

Today, as Syria faces the desperate prospect of an open-ended civil conflict, traumatised by its 20,000 dead and 250,000 refugees, it may seem trivial to mourn the speed with which its archaeological and architectural heritage is disappearing.

But while the human pain is immeasurable, the destruction of a people’s heritage is irretrievable: once a monument is destroyed, it can never be replaced. With modern weaponry it only takes a few months for the history of an entire people to be reduced to rubble.

Groups like the World Monuments Fund are monitoring the losses. There has been serial looting of Syrian museums and archaeological sites, especially from the museums at Idlib, Dura Europos and Palmyra.

Terrible damage has also been done to some of Syria’s most spectacular monuments, such as the souks, citadels and the Umayyad mosque of Aleppo, the ancient cities of Palmyra and Apamea, and several of the country’s crusader castles, including the greatest of them all, Krak des Chevaliers.

The old city of Homs has been levelled, and with it two major museums, several early Christian churches and a number of Ottoman mosques.

As in Afghanistan, there is evidence the looting is highly organised. A Lebanese antiquities dealer recently told Time magazine that he was making a fortune from would-be Syrian freedom fighters who were selling him priceless Syrian antiquities for very low prices and buying arms at inflated rates.

But an even more irretrievable loss than the antiquities (which potentially can be bought back) or monuments (which can sometimes be restored) is likely to be the ripping apart of Syria’s closely woven sectarian patchwork.

Until two years ago, Syria was the last country in the Middle East to retain its richly mixed Ottoman inheritance. Now, as happened before in Greece, Turkey, Egypt and the Balkans, civil war is leading to a consolidation of the majority community and the exile of the minorities.

One of the distinguishing features of pre-civil war Syria was the way it sheltered so many ethnic and religious groups that had disappeared elsewhere. As well as the dominant Alawites there were large minorities of Kurds, Armenians, Circassians and Druzes, as well as more arcane groups such as the Yezidi, Mandeans (a Gnostic sect) and the Urfalees.

Judging by precedents in other former Ottoman countries, it is these minorities that are most likely to disappear in the next few months.

When the uprising in Syria began at the height of optimism about the Arab Spring, there were hopes it would usher in a new dawn of freedom and democracy. Today the future looks immeasurably grimmer, and what kind of Syria will be left standing after the firing ceases is a prospect few now even wish to consider. — The Guardian, London