[...] sniping among Kurdish factions makes the hold on the town seem shaky and is threatening the wider fight against Islamic state militants. Overlooking the strategic northern Iraq town of Sinjar, peshmerga fighters representing the recognized authorities of Iraqi Kurdistan fume against what they see as the recklessness of their supposed allies in militias drawn from neighboring Syria and Turkey. Within the bomb-scarred warrens of the town below, foot soldiers in those militias complain that the much more heavily armed peshmerga have done too little during the fight against Islamic State fighters holed up within easy range of a sniper's bullet. Tens of thousands fled to the nearby mountains, creating a humanitarian disaster, when IS militants seized the town in August and unleashed a wave of terror involving killings, imposed conversions and forced marriage. The Kurds, in their various forces, have provided the most effective ground resistance to date against the jihadis who have taken large swaths of Iraq and Syria — and so the outside world has a stake in their ability to continue that struggle. Since December, the peshmerga and their Kurdish comrades in arms have regained the mountains in this area thanks in part to increased weapons supplies and airstrikes from coalition warplanes. The factions include the Turkey-based Kurdish Workers' Party (PKK), the Syria-based People's Protection Units better known as the YPG, and Yazidi-led forces billing themselves as the Sinjar Resistance. The PKK and other anti-IS forces in this part of Old Sinjar transport soldiers between a rear headquarters and front-line posts using a home-armored Nissan Patrol that, weighed down with extra metal plating, struggles to navigate the town's rain-soaked dirt roads. Contrary to the primitive weaponry used by fighters with the other Kurdish factions, the peshmerga front line is equipped with heavy machine guns and mortars.