When a ceasefire is not really a ceasefire
Albert Einstein, whose theories were finally proved conclusively this week, once said that: "You cannot simultaneously prevent and prepare for war."
In some sense, this is what seems to have been done with the cessation of hostilities in Syria. The intention was to clear a space for humanitarian aid, vital to save millions of lives. It might also allow for a more uncluttered theatre to take on Isil. But attempting to square the divergent interests amongst the diverse players seems too tall a diplomatic order.
There is also the small matter of the fact that all of the foreign actors currently participating in the war can carry on bombing as they please.