No I don't think there is. As I said earlier. Or at least, if there is no one has got to the stage of working it out.
The first answer, years ago, was UN sanctions against Assad, as it was really he who was plainly stirring a major conflict by his actions. But that got nowhere because Russia and China intervened, and there was, rightly and understandably, no appetite for a military intervention.
The next idea was support for the moderate rebels, who at the start were THE rebels, but that was problematic as progress was slow and the sheer brutality of the government offensive drove many more people in the ranks of the more extreme groups.
And meanwhile all sort of other groups,: IS, the Kurds, the Turkmen, all staked their pitch.
Then there was the chemical weapons fuss, when we patted ourselves on the back that we'd made Assad give them up, when actually all he really did was increase his non-chemical barrel bombing of civilians.
For all that, it looked like he was on the way out, and ceasefires were starting to break out between rebel groups and his exhausted army.
It was then that the Russians intervened.
So a series of worthwhile but doomed plans have failed, and now brute force is being redoubled in a frantic attempt to reclaim as much of the country as possible for the regime.
And we get to the stage, to return to aog's original question, where an admittedly unconventional and outspoken foreign secretary has spoken out against the latest developments.
I'd almost forgive Boris his Brexit period :-)