The group are wiping out rivals and taking areas of strategic interest to Turkey and Bashar Al Assad's government. Al Qaeda-linked militants in Syria are strengthening their grip on territory in western Aleppo’s rebel-held countryside, nearly 18 months after taking most of the neighbouring province of Idlib. A sudden campaign by Hayat Tahrir Al Sham last week caught Turkey and allied rebels by surprise (when they moved their forces to attack the Kurds near Manbij)... “Tahrir Al Sham chose the right moment to attack.”