The best hope for an end to the killing in Syria is for the United States and Russia to push both sides in the conflict to agree a ceasefire in which each holds the territory it currently controls. In a civil war of such savagery, diplomacy with any ambition to determine who holds power in future will founder because both sides believe they can still win.
There appeared to be an opportunity for productive talks after it was announced on 7 May that the US Secretary of State, John Kerry, and his Russian counterpart, Sergei Lavrov, had agreed to hold a peace conference on Syria in Geneva. The US, Russia and Iran could see themselves being sucked into an ever more violent conflict and one that is rapidly spreading. It is destabilising Syria's neighbours in Jordan and Lebanon as Shia and Sunni support opposing sides. Even Turkey's new-found prosperity is vulnerable as a result of its whole-hearted backing for Syria's rebels.