Western and Arab military advisers based in Amman have quietly stepped up their role on Syria’s southern front, helping win recent advances for opposition factions.

After weeks of heavy fighting, rebel groups announced the seizure of 80 per cent of Qunietra province on Saturday, including areas along the border with Israel. The territory could prove to be a key link between opposition forces in the south and those fighting in and around the Syrian capital.

Qunietra borders the south-west side of rural Damascus and rebel commanders say they will now be able to work on establishing a reliable supply chain to besieged opposition units in districts on the western and southern sides of the capital, areas that have been largely cut off by regime troops since last summer. […]