More to the point, stopping Isil from growing is one thing. Taking their land is another. In Iraq we can draw on local troops, as hapless as they sometimes are, but in Syria the only acceptable forces – David Cameron’s infamous 70,000 moderate rebels – are not only divided across hundreds of factions, but view Assad as the primary enemy. The US and Russia are discussing ways to remove Assad, but the so-called Vienna process envisages a new government only in mid-2017. Russia is now dragging its feet, hoping that we come round to backing Assad without Moscow having to give up anything. US Secretary of State John Kerry, who over four years of Syria diplomacy has perfected the art of placing his feet in his mouth, has inadvertently encouraged Moscow in this belief, with statements such as “the United States and our partners are not seeking regime change in Syria”. Yet the issue is simple: until it’s clear that Assad really is committing to give up power eventually, it’ll be politically impossible for Western countries either to co-opt rebels or to work with Assad’s army or Putin’s air force. So who will storm Raqqa?