Now the hope is that Mr Assad will change his behaviour. But what about the wider Syrian conflict? This brutal war shows no sign of ending. Many have pointed out that it is barrel bombs, artillery and bullets that are responsible for the overwhelming bulk of the deaths and mutilations in Syria, not chemical weapons, and yet it is these that prompt Western action.
There is a good measure of truth in this sentiment, though for historical and cultural reasons chemical weapons have a particular horror in the West in the wake of their use in World War One. The treaty banning them is an important disarmament agreement and its weakening threatens to unwind years of progress.
But the wider question is to what extent these latest strikes change the picture in Syria? Do they bring the conflict any closer to an end? Sadly the answer is almost certainly no.