LONDON: The defection of Syria’s ambassador to Baghdad marks the second time in a week that Bashar al-Assad has been deserted by a top ally, suggesting that the isolation of the Allawite core of the regime is accelerating, and that the conflict is sliding inexorably into a primarily ethnic civil war.

Like Manaf Tlass, the Republican Guard general whose defection became known last Thursday, Nawaf al-Fares is part of the Syrian Sunni elite, whose alliance with the Assad family and the Allawite security apparatus was the pillar on which the Syrian Ba’ath party regime was built. As that pillar crumbles, what is left is a heavily armed, highly militarised Allawite minority with its back to the wall in the face of a vengeful, if fragmented, Sunni majority.

Al-Fares is an especially significant figure. His selection by Assad in 2009 as Syria's first ambassador to Baghdad in three decades was a high honour reflecting his status in Syrian society. He was the head of the Ba’ath party in his home city of Deir ez-Zor, the seventh largest in Syria, as well as serving as governor of the sensitive Quneitra province, along the Israeli border.

Most importantly, Al-Fares is the Syrian head of the Uqaydat tribe which straddles the Syrian-Iraqi border along the Euphrates river. They and other border tribes have long been a powerful force in the region’s history and some observers see them as the key to Assad’s survival.

Salman Shaikh, the director of the Brookings Doha Centre said: “This is actually more important than the Manaf Tlass defection because of where Al-Fares comes from and his tribal connections. The one thing the regime should fear more than anything else is a new front in the east. Its efforts to dampen down the revolt there, particularly in Deir ez-Zor, have had clear political consequences.”

Until now, like the Kurds, these big border tribes have sat on the fence, unwilling to turn against Assad too early for fear of sharing the fate of the Shia of southern Iraq who rose up against Saddam Hussain in 1991 thinking they had US support, only to find they were on their own and massacred by the Iraqi Republican Guard. It was a bloody and salutary lesson no one in the region has forgotten.

The ambassador's defection realises the highest hopes of the Syrian opposition, that the defection of the Tlass family would embolden other members of the Sunni elite to break with the regime. What seems to be holding that elite in place is principally fear of what would happen to their families if they fled. The Tlass family managed to get one member after another out of the country before Manaf, the general and childhood friend of Bashar al-Assad, made his run for it. The clan's homes in Damascus have been since comprehensively trashed by the security forces. Al-Fares, as a powerful tribal leader, would also have had the wherewithal to protect his family before announcing his defection.

For others it will be harder. Reports from Damascus say that prominent Sunnis are being pulled in for questioning and are having their passports confiscated. But such treatment in itself will loosen the habitual bonds of loyalty.

By arrangement with the Guardian