Kurdish peshmerga forces are at the forefront of the international battle against the Islamic State group in Iraqi Kurdistan. Thousands of civilians were forced to flee their homes when the jihadists overran several cities, but aided by international coalition air strikes the Kurdish forces have managed to retake lost ground. They have also set up checkpoints across more than 1,000 kilometres of Kurdish border. Edith Bouvier and Guillaume Bression report from the frontline.