The attack on Syrian civilians that provoked the western response at the weekend made for an appealing conspiracy theory. And that theory had been widely bandied about as nations debated the merits of a retaliatory strike.

I have heard people who are no fans of Bashar al-Assad argue that it is absurd to blame him for the suspected gassing. What interest did he have in crossing a western red line when no one was calling any longer for his demise? The attack, the theory goes, must have been staged by the opposition.

The Syrian regime, however, operates on a different logic, one that allows for unspeakable brutality even when that appears counter to its interests. The same applied to Saddam Hussein, the late Iraqi dictator, whose rule was terminated only with an outside invasion.