Yet this cannot explain the most striking development of the last year, namely that Isil and Assad have both grown stronger in parallel. When Abu Bakr al-Baghdadi carved out his “Islamic State” in the desert sand, he was not always struggling against the regime’s bitter opposition; on the contrary, his advances were often helped by Assad’s offensives against rival rebel factions. In other words, Isil has not achieved its victories in the teeth of dogged resistance from the secular dictator; rather, Baghdadi has been enabled by Assad’s pitiless campaign to hold power.