In the Old City of Damascus, the Syrian war drove eight Christian brothers to take up arms to defend their community from insurgents they saw as an existential threat.Two of the Dawoud brothers, born and raised in the ancient Christian quarter of Bab Touma, were killed last September battling jihadists who have come to dominate the insurgency against President Bashar al-Assad.sign up to our newsletterPictures of them, dressed in military fatigues, mark the way to the 17th century house hidden in a warren of alleyways where the six surviving brothers still live with their families, each in their own quarters arranged around a central courtyard."This is a battle of life or death," said Ibrahim Dawoud, 53, a picture of his two late brothers, killed fighting an al-Qaeda linked group, swinging in a hefty pendant from his neck."I teach oriental music, but at the same time we love our people and we can't allow them get anywhere near our people."The Dawouds are a sample of the support base that has helped the government through the war about to enter its fifth year.At the start of the Syrian conflict, which grew from protests against Assad's rule, the army became stretched and suffered defections to the rebellion. The government raised dependable militias to help in the fight.Known as the National Defense Forces and believed to number in the tens of thousands, they, along with other loyalist militia, help to ensure the state remains by far the strongest party to a conflict estimated to have killed 200,000 people.Many Christians are staunch Assad supporters. They look to him for protection against jihadists including the Islamic State group, whose brutal methods including beheadings and forced conversion have terrified minorities and mainstream Muslims alike.The two Dawoud brothers killed in September - Amer and Bashar - had fought in a number of battles around Damascus and further afield, said Naji Dawoud, 49, another of the brothers.These included the battle for Yabroud, a town near the border with Lebanon won back from insurgents a year ago with the help of the Lebanese group Hezbollah. Ibrahim Dawoud, the music teacher, venerates the Shi'ite Islamist group and its leader, Sayyid Hassan Nasrallah, in a song played on his lute.In his living room next to a pair of stereo speakers, Naji displays the casing of a rocket which he proudly says he fired during a battle in Jobar - a district on the eastern Damascus outskirts from where insurgents routinely fire mortar bombs into Bab Touma. One of them hit the Dawouds' house in January."As I fighter, I say that as their will to displace us increases, so does ours to defend ourselves and to attack them," said Naji, wearing a green camouflage jacket with the NDF badge sewn on the right shoulder.He lifted his jacket to reveal the scars where he says he was shot by Muslim Brotherhood militants in the 1980s while performing his military service.On his computer, he has saved a link to online footage posted at the time of the Dukhaniyeh battle showing the bodies of his two brothers. The Syrian Observatory for Human Rights, which tracks the war, identified the insurgents in Dukhaniyeh as members of the al Qaeda-linked Nusra Front."There is not one corner where my two martyr brothers did not fight," said Naji. "If another one of us is martyred, we will continue."The Dawoud brothers are on the constant look out for strangers in Bab Touma, which they patrol with other NDF members who man checkpoints painted in the national colors and adorned with pictures of Assad.When the mortars hit, they help to ferry the wounded to hospital: a neighbor in her late 80s was killed in one recent bombardment. "As far as we are concerned," said Ibrahim Dawoud, "the most important thing is our homes, our neighborhood."