When it comes to the politics of intervention, history can obscure as much as it can advise. Even the proposition that it is now “too late” to save Syria rests on the assumption that its fate is about to follow a recognisable path, for which there is a precedent.
It was as long ago as 1859 that John Stuart Mill suggested we might try to establish “some rule or criterion whereby the justifiableness of intervening in the affairs of other countries, and (what is sometimes fully as questionable) the justifiableness of refraining from intervention, may be brought to a definite and rational test”.