An official at the United Nations Educational, Scientific and Cultural Organisation (Unesco) headquarters in Paris said the outlook for safeguarding Syria's cultural jewels was bleak.
"There have been several repeated expressions of concern over heritage and also great concern about human life. There has been nothing to alleviate that concern," the source told the Herald.
Syria hosts a long list of Unesco World Heritage sites, considered to be part of the world's patrimony for their exceptional contribution to civilisation and nature.
"Along with Mesopotamia, the country reflects the main advances made by humankind, meaning the birth of the first villages or the evolution from the state of predator to sedentarism," said Marc Griesheimer, head of archaeology and antiquities at the French Institute of the Near East.
Syria's valleys and deserts hold many treasures, some of which are never visited by mainstream tourists for the totalitarian regime rarely encourages visitors.
Palmyra in the east and Aleppo in the north have astonishing remains that date from the second millennium BC while in the south lies Bosra, the former capital of the Roman province of Arabia. To the west lies the Krak des Chevaliers, the best-preserved Crusader fortress in the Middle East and an edifice that looks as if it is straight out of an Indiana Jones movie.
The capital Damascus vies with Aleppo for the title of the oldest continuously occupied city in the world. In its heart lies the 7th-century Umayyad mosque, one of the world's largest, oldest and holiest Muslim shrines. Built around a shrine said to contain the head of John the Baptist, it nestles in a warren of narrow streets that abut the road where St Paul was said to be struck by divine light.
Concern for these sites is amplifying as the regime of President Bashar al-Assad fights an ever more brutal and desperate bid for survival, using tanks, artillery and helicopters to keep guerrillas at bay.
In March, gunmen broke into the Krak des Chevaliers, threw out the staff and began looting the site. Across northern Syria there has been fighting around the 40 villages which dated from the first century and feature preserved dwellings, temples, churches and cisterns. The villages were added to the Heritage list last year. In Palmyra, where roman colonnades and a temple to the god Vaal have stood for 2000 years, troop fortifications have damaged parts of the ruins, according to a European Union conservation group Euromed Heritage.
Unesco has to be careful though about how and when to make its calls for moderation.
To be silent or too low-key means that belligerants can ignore international concern. In 2001, the giant buddhas carved into the rock cliffs of Bamiyan, Afghanistan, were destroyed by the Taleban as they sought to rid the country of non-Muslim influences. Unesco at the time was accused of moving too little and too late to urge restraint.
Conversely, though, combatants can destroy relics in an act of sheer spite to those who have asked them to stay their hand. This was the case last month when Islamist militants from the Ansar Dine group in Mali, wielding pickaxes and shovels, wrecked ancient mausoleums in the fabled city of Timbuktu.
Beyond appeals, Unesco's options are few.
"Unesco does not have an army, it does not have much of a punitive potential of force," the official said, speaking on condition of anonymity. "Destroying the enemy's heritage at a time of war is a war crime and as such can be tried by the International Criminal Court. It is not sufficient to deter some groups and some regimes. But, in the case of Syria, it goes towards building up a possible case against Assad."
After conflict, heritage sites may run even greater risks. Administrative chaos, poverty, lack of guards and corruption are hefty encouragements for looters.
"The problem of looting is rarely focused on once the war is over," said Cunliffe.
"During and after the wars in Iraq, looting increased to disastrous proportions, affecting hundreds of sites.
"When items are looted from unexcavated sites, as is often the case, we cannot possibly know what has been taken, making it much harder to return the stolen items to the country [which owns them], and by removing objects from the site of origin, huge amounts of information are also lost.
"It's a tragedy."
