All this is tardy but nevertheless welcome, and it may yet rescue the Government’s open-ended air campaign against Isil from drifting into irrelevance. There is much that the US and the UK can add to the new coalition’s command-and-control centre to be established in Riyadh. A coordinated air/ground campaign is now a genuine prospect. Indeed, Isil fighters know that ground forces are coming for them in Mosul, Palmyra and Raqqa, because they are making elaborate preparations. When they do come, the resulting battles will be desperate and hard on public sensibilities.