Fear forges unlikely alliances with IS extremists Building coalitions: Fighters from Islamic State march through Raqqa, Syria in January. Beirut: Some rebel groups are so small they do not bother to announce their existence, appearing only in the dead of night to conduct "assassination runs" against key Islamic State targets in eastern Syria. Others, particularly along Syria's mountainous border with Lebanon, are planning new mergers between non-Islamist groups as they watch with alarm as brigades formerly affiliated with the more moderate Free Syrian Army pledge their allegiance to the extremist Islamic State. In the constantly shifting alliances on Syria's bloody battlefields, with many groups desperately short of weapons and ammunition, any long-lasting dent in the fortunes of either the brutal regime of President Bashar al-Assad or IS has yet to be realised. Cooling down: A Syrian Kurd pours water on a child after they crossed the border between Syria and Turkey in September, fleeing with thousands from Islamic State fighters who advanced into their villages. For some it is a clear case of "join with the Islamic State or die, either by starvation or at the hands of Daesh," one Syrian rebel fighter told Fairfax Media, using an Arabic term for IS. Trapped in the middle and seemingly all but forgotten by the US-led international coalition conducting bombing raids on IS positions in Syria and Iraq are the civilians who have lived through more than three years of war. Facing their fourth freezing winter without the most basic necessities, at least 6.5 million Syrians are internally displaced - half of them children - and more than 3.2 million have fled, mostly to neighbouring Turkey, Lebanon, Jordan and Iraq, the latest United Nations figures show. Front line: Kurdish peshmerga fighters advance during clashes with Islamic State on the front line at Buyuk Yeniga village in September. The military mergers, big and small, IS and non-IS alike, represent an attempt to shift the power balance on the front lines and in some cases win the favour of Western backers who are looking to fund moderate groups to push back against the radical Islamic State, said a retired general who did not want to be identified. There have been two mergers of note this month, says a Free Syrian Army fighter from a brigade based in Qalamoun, the scene of recent fierce battles and just across the border from the Lebanese town of Arsal where a group of Lebanese soldiers were kidnapped in the worst spill-over of the Syrian conflict into Lebanon. Two brigades, one formerly affiliated with the Free Syrian Army, the Qasyr Brigade, and the independent Farouk Brigade - each with about 50 fighters - publicly pledged their allegiance to IS on November 9 in a video released on YouTube. A propaganda image of IS fighters raising their weapons as they stand on a vehicle mounted with the trademark Jihadists flag in Anbar province. When asked why two non-Islamist brigades would join the radical Sunni movement of IS, the fighter, who did not want to be identified said: "100 per cent they merged because of their need for equipment and because of their fear of IS "For now there will be no impact on the front lines and we are using this time to form our own grouping with the FSA that we will announce soon," he says. It is a pre-emptive measure on our part given all the alliances that are forming around us. Across the other side of the country, in the eastern city of Deir al-Zor, an activist known as Abd Abdel-Rahman who has observed at close quarters IS fighters, the brigades that fight under its umbrella and those who fight against it, says most groups in the area are aligned with IS. Against this all-powerful group, there are a handful of small groups fighting IS, Abdel-Rahman says, such as al-Kafan al-Abyad and Saraya al-Mawt. "They are more like illusions as they do not have a big base of followers," he says. Members of these groups may target and assassinate IS members in places where IS has a strong presence such as Bou Kamal and al-Mayadin but their actions do not have a clear effect on the strength of IS. On a larger scale, recent rumours of a merger between IS and the al-Qaeda-linked Jabhat al-Nusra have, so far, proved false, says Aymenn Jawad al-Tamimi, an expert on jihadi groups in Syria and Iraq. "Nusra, in the long term, does not support the Islamic State's idea of a caliphate ... and it would dent Nusra's reputation to align with them considering how much effort IS puts into taking over other areas by military force," says Tamimi, who is also a fellow at the Middle East Forum and a researcher at the Interdisciplinary Centre Herzilya. "The rumours that IS had provided Jabhat al-Nusra with military assistance to fight the Syrian regime forces came from rebels who are being backed by the West," he says. They are saying: 'the jihadis are all rallying against us so give us more weapons'. It doesn't mean, however, there have not been attempts to forge some kind of truce between the two groups, Tamimi says, given many non-Nusra jihadis have a specific policy of not fighting the Islamic State. Instead, they believe all jihadis have the same end goal and should not fight each other. Ultimately, he says, the failure to forge lasting alliances on Syria's fast deteriorating front lines "undermines the general jihadi propaganda that all jihadis are brothers - they all have the same end goal of a global caliphate but the human temptation to divide and form their own groups is far stronger in the end than their ideological bonds." Against this background is the Islamic State's desire to maintain and expand its base after it seized swathes of Syria over the last 18 months and swept into northern Iraq in June, declaring a caliphate over the cross-border territory it controls. Since then, fuelled by the millions it makes from its control of eastern Syria's oil fields, the illegal taxes it collects via extortion and the ransoms paid for kidnap victims, IS has moved from the northern Iraqi city of Mosul to Tikrit and into the western Anbar province. Along the way the self-declared leader of the caliphate, Abu Bakr al-Baghdadi, has been accepting pledges of allegiance from supporters of the Islamic State from Libya, Egypt, Yemen, Saudi Arabia and Algeria. Earlier this week, in a recording purported to be Baghdadi released after he was reportedly injured in a coalition airstrike in Iraq, he said: "We announce to you the expansion of the Islamic State to new countries, to the countries of the Haramayn, Yemen, Egypt, Libya, Algeria." He urged his supporters: "Oh soldiers of the Islamic State ... erupt volcanoes of jihad everywhere. Baghdadi singled out Islamic militants in Egypt's north Sinai region - responsible for a spate of suicide attacks and car bombings which have killed dozens of Egyptian police and security forces - for rising up against the "dictators of Egypt." Soon after Baghdadi's speech, the Egyptian militant group Ansar Beit al-Maqdis, which just over a week ago swore allegiance to Islamic State, changed its name to Sinai Province, or Wilayat al-Sinai. The Sinai group's pledge of allegiance is significant, says Tamimi. "It is the first official step of dropping the distinct group identifier and adopting the Islamic State, and you are also seeing this in Libya now ... that traces back to the jihadis in eastern Libya, especially from Derna," he says. The move by Ansar Beit-al-Maqdis - which was initially labelled an al-Qaeda-linked group - could be read in two ways, says Aaron Reese, the deputy research director at the Washington-based Institute for the Study of War. "It is significant in that it shows the Islamic State is having success in spreading its ideological message to other groups, that there is some resonance there to their program," he says, and also suggests a repudiation of al-Qaeda given the tensions between al-Qaeda and IS. But it could also represent a negative for the group if its traditional routes of smuggling money, fighters and weapons are closed off to it due to its new allegiance with IS, he says. This pledge will undoubtedly result in the Egyptian government redoubling its operations in the Sinai. In the meantime, IS has experienced some setbacks - they have been all but pushed from the key Iraqi oil refinery in Baiji and there have been increased bombing raids on key IS targets, Reese says. "It is not surprising that pledges of allegiance are coming in at the same time as the setbacks - the IS has made its successes very public and its failures less so," says Reese.