Syria rebel offensive against jihadists seeks to regain West support
Competition for control of Syria's opposition areas and a desire to regain Western support after a suspension of aid are key factors behind a huge rebel offensive against radical jihadists, experts say.
Fierce battles have pitted three massive Syrian rebel coalitions against the Islamic State of Iraq and the Levant (ISIL), which has roots in neighbouring Iraq and was until recently an ally of the rebels in their war against President Bashar al-Assad.
"A combination of local and external factors has given rise to this 'sacred union' against ISIL," said Romain Caillet, an expert on contemporary Salafism.
Locally, "relations between ISIL and all other opposition brigades have deteriorated," said Caillet, adding that the rebels "did not accept ISIL's bid for hegemony over all the liberated territories."
The many abuses committed by ISIL have only aggravated the tensions, said Caillet, a researcher at the French Institute of the Near East.
They include the death of a popular rebel doctor linked to the powerful Ahrar al-Sham brigade.
Known as Abu Rayyan, he was reportedly kidnapped, tortured and killed by ISIL. His death was reported last week.
"The killing under torture of an Islamic Front commander in an ISIL prison was a profound shock to public opinion in Aleppo province, which is what allowed this vast offensive against ISIL," Caillet added.
Multiple assassinations and kidnappings blamed on ISIL since summer 2013 pushed rival rebel brigades to declare war against the extremist group.
"ISIL's behaviour had become unbearable for most armed groups," said Thomas Pierret, another expert on political Islam in Syria.
Of particular concern to rebel groups were ISIL's "attempts to take control of frontier regions, blocking off the rebels' logistics," he added.
"Many groups have wanted to act for a long time, but they were blocked by the reluctance of Ahrar al-Sham, which cooperated closely with ISIL" in parts of northern Syria, Pierret said.
The group, a key member of the Islamic Front rebel alliance, "probably gave its green light after ISIL attacked one of its bases in Aleppo and executed the doctor" Abu Rayyan.
"Several groups were also encouraged by the fact that many ulemas (clerics), including advocates of jihadist ideology, condemned ISIL's behaviour," Pierret said.
The jihadist Al-Nusra Front, which includes non-Syrians among its ranks, has been active since early 2012 in the fight against President Bashar al-Assad's regime.
In April 2013, the head of Al-Qaeda's Iraq affiliate, Abu Bakr al-Baghdadi, announced that his group was active in Syria and said Al-Nusra and AQI would merge to form the Islamic State of Iraq and the Levant.
But Al-Nusra rejected the merger, pledging allegiance directly to Al-Qaeda, and the two groups now function separately on the ground.
According to Caillet, most of ISIL's military commanders are Iraqi and Libyan, while most of its religious leaders are Saudi and Tunisian.
Its fighters on the ground in Syria, however, are mainly Syrian.
'Making a good impression on the West'
The exiled opposition has expressed its support for the rebel war against ISIL.
The key opposition National Coalition has accused the jihadists of having "stolen" the revolution against Assad.
For its part, ISIL has claimed it is target of a "media campaign" aimed at "demonising" it.
Caillet believes external factors are also at play in the new fight against ISIL.
"The opposition wants to make a good impression on Western governments" by disowning the jihadists, he said.
On December 11, the United States and Britain suspended their non-lethal aid to the opposition, fearing the growing influence of radical Islamists in the conflict.
Pierret believes "some rebel groups may have acted this way hoping that the United States will help them".
"But I seriously doubt that it will work given the American strategy of disengagement" from the region, he said.
Bassam Abu Abdallah, an expert with close ties to the Assad regime in Damascus, believes the rebel-jihadist fighting is linked to peace talks slated for January 22 in Switzerland.
"This battle is aimed at justifying invitation letters sent to Islamist groups to attend Geneva 2," said Abdallah, who heads the Damascus Centre for Strategic Studies.
These groups, "financed by the Gulf, (seek to) give the impression that they are fighting terrorism as defined by the West," he said.