Two things are crucial now. Firstly, Syria needs to follow up its declarations about the monitoring and destruction of chemical weapons with verifiable action.

Secondly, having to date functioned as the dictator's protecting power, Russia needs to finally put enough pressure on the regime to stop it playing for time.

Diplomacy does have a chance here once again, but it can only be used if everyone credibly commits to it. We expect the Assad regime, having applied for accession to the Chemical Weapons Convention, to act in the spirit of that Convention from day one.

The UN inspectors’ report will presumably deliver certainty about the terrible use of chemical weapons on 21 August and implicitly enable conclusions to be drawn about who was responsible. It is our view that the international mechanisms for criminal proceedings, as established in the form of the International Criminal Court, will then need to be brought to bear.