Amman // A new push by western and Arab-backed rebel forces is under way in southern Syria to defeat ISIL factions dug in close to the Jordanian and Israeli borders.

As the struggle against the extremist group gains pace in Fallujah in Iraq and the north and east of Syria, with US special forces fighting on the ground alongside Kurdish militia units, a third operation against ISIL affiliates has begun with far less fanfare in the south.

The campaign has been orchestrated by Military Operations Command (MOC) in Amman, the secretive centre staffed by army and intelligence officers from the US, UK and Arab Gulf states which has played a central role in arming and organising rebel forces fighting against Bashar Al Assad.

A UN-brokered ceasefire – frayed but more or less holding – has largely halted combat between pro and anti-Assad forces in the south. This has freed up an alliance of moderate rebels to launch a concerted attack on ISIL, opposition commanders on the southern front said.

While the main rebel force remains in place to deal with any ceasefire breaches by pro-Assad forces, about 4,500 fighters, including groups trained in night-time warfare tactics by US special forces in Jordan, have been retasked to assault ISIL positions at Jumleh, Shajareh, Qweyeh, Beit Arar, Abdeen and the Sehm Al Jolan Dam – all in Deraa province.

An ISIL training camp in the south-eastern desert at Hosh Hammad is not on the rebels’ target list because it is beyond their range.

Rebels in contact with the MOC said maintaining the ceasefire, thus creating an opportunity to attack ISIL, was a strategy advocated by the Americans and British.

In a series of written messages sent to rebels this month, the MOC urged them to confront ISIL. In one message, the MOC criticised rebels for delaying operations “despite the fact we have provided you the means” for attacking ISIL. “The supporting countries [in the MOC] are tired of your excuses,” the message read.

The anti-ISIL campaign in the south technically began on March 21, according to a senior rebel commander involved in the effort, but it failed to achieve the hoped-for breakthroughs early on, prompting a reorganisation, revision of tactics, weapons resupplies and more pressure from the MOC.

Last week the command centre warned rebels it would cut cash flows unless they began to score military successes against ISIL in the south. For each day they delayed in making progress, they would be docked a week’s worth of funding, the MOC told commanders.

Rebel fighters who volunteer to take part in battles against ISIL are given bonus pay. While fighters involved in combat against pro-regime forces typically receive $50 to $100 (Dh180 to Dh370) per month from the MOC, those involved in anti-ISIL operations receive between $100 and $250 a month.

In Syria’s southern region ISIL has not achieved the kind of spectacular advances it made in eastern Syria and western Iraq. Nonetheless, powerful factions affiliated with ISIL have seized territory in south-west Syria, less than 100 kilometres from the Jordanian capital.

The two main ISIL affiliates in the area, Harakat Al Muthanna and the Yarmouk Martyrs Brigade, announced a merger last week, joining together as the Khalid Bin Walid Army. Fighters from Jaish Al Jihad, led by Abu Musab Al Fannousi also joined. The reorganisation appears to have been in response to the growing pressure against them from moderate rebel factions.

There had been reports of a similar merger in April, which were denied at the time by Harakat Al Muthanna. Whatever reservations the group had appear to have been overcome since then.

Both Harakat Al Muthanna and the Yarmouk Martyrs Brigade have denied being part of ISIL but have made little effort to hide a shared ideology, and have frequently used the same flags and praised ISIL.

The Khalid bin Walid Army is under the command of Abu Uthman Idlibi, according to MOC-affiliated rebel sources. He had not previously played a high-profile role in the south, only rising to prominence since the former commander of the Yarmouk Martyrs Brigade, Mohammad Abu Ali Al Baradi – commonly know as Al Khal, or “the uncle” in Arabic – was killed in November. His history remains unclear.

According to a Syrian security source familiar with MOC operations, Abu Uthman Idlibi, a nom de guerre, is a Syrian from the northern city of Idlib, who fought against the Americans in Afghanistan and Iraq post 9/11. He is believed to have crossed into Raqqa from western Iraq as the uprising against the Syrian president morphed into a civil war, a conflict that, after 2013, was increasingly dominated by extremist factions. From Raqqa, the capital of ISIL-controlled territory, he was deployed to the southern region to head up, and unify, affiliated forces.

The move appears to have paid off. MOC-backed rebel commanders said Abu Uthman Idlibi had overseen a robust defence plan for areas under his control. Outer defence cordons had been breached but assaults by MOC factions had ultimately been repelled by disciplined small-arms fire from well dug fighting positions, in addition to well laid minefields and accurate mortar fire.

Moderate commanders also admitted there was limited popular appeal to the fight in Deraa province. While they said they agreed defeating ISIL had to be a priority, some rank and file rebels do not view Harakat Al Muthanna and the Yarmouk Martyrs Brigade as fully fledged ISIL factions. Others insist that pro-Assad forces must remain the focus of their efforts, and that attacking ISIL is a waste of resources.

Harakat Al Muthanna and the Yarmouk Martyrs Brigade have also been successful in carrying out a string of assassinations against MOC-affiliated rebels during the past year, and have threatened to target anyone taking part in attacks against them.

Most recently, a leading southern front weapons trader, known as Cheg Cheg, was killed in a bomb attack on April 27, in what was a significant blow to rebel supply lines. MOC-affiliated rebels say Harakat Al Muthanna and the Yarmouk Martyrs Brigade were probably behind the attack because Cheg Cheg had armed units fighting them.

Just as ISIL has streamlined its command-and-control in the south, so too have the MOC-affiliated rebels. The anti-ISIL effort is being led in the field by Najim Abu Majid. He heads the rebel operations room tasked with overseeing combat operations against ISIL. Two other support operations rooms have been put in place to provide fire support and reinforcements to his front-line units.

Under pressure from their backers, particularly Jordan and Saudi Arabia, MOC-affiliated rebel factions are also undertaking a renewed effort to cut back the number of unit commanders, from more than 50 to 10. Each would have responsibility for a specific geographic area, as and when the fight against pro-regime forces resumes.

“The MOC wants to reduce the number of commanders and to better integrate the different units,” said a senior rebel familiar with the effort.

Previous reorganisation moves on the southern front have led to turf wars and bruised egos but, ultimately, have helped create a rebel alliance capable of scoring victories against forces loyal to president Al Assad. Regime forces have been supported by Russia and Iran. In the months leading up to the UN ceasefire however, rebels had suffered setbacks, notably losing the town of Sheikh Miskeen to pro-Assad troops.

foreign.desk@thenational.ae