When Islamic State overran Palmyra last week, amid Western horror over the beadings and probable destruction of the city's Roman remains, another - perhaps still more significant - event was missed. In Idlib, a coalition of rebels had defeated government troops, cutting the Syrian regime's forces off from the north. Bashar al-Assad, Hizbollah and their Iranian allies are now retreating on multiple fronts and control just 20 per cent of Syria. They have lost all the border crossings to Iraq and now Homs and Aleppo are under threat, as well as the roads from Damascus to the coastal Allawite enclave. Three recent speeches by Hassan Nasrallah in which the Hizbollah leader sought to cover up his forces' failings with bluster and threats against Israel are more evidence of the pressure that the pro-Assad coalition is now under. A post-Assad Syria looms, controlled by a patchwork of fundamentalist militias ready to turn on the West. The notion of Israel as the West's buffer against a tide of jihadis bent on its destruction becomes ever more real.