The Saudi, Qatari and Emirati governments know full well that the Muslim states that are taking in Syrians are already overwhelmed by the numbers. According to Amnesty International, Turkey alone has 1.6 million--and it, at least, is economically stable. The same can hardly be said for Lebanon (1.1 million refugees), Jordan (620,000), Iraq (225,000) or Egypt (140,000). And these are the refugees who have registered; it is hard to know how many others have crossed into these countries, but have not been counted.

The oil-rich Gulf Arab states might argue that they are giving all these countries financial aid, to help them cope with the refugee crisis. This is not enough. Money cannot paper over the tremendous social and political strains on the smaller countries: the refugee numbers are equal to a quarter of Lebanon's population, for instance. Nor can cash make up for the huge drain on natural resources. Jordan's water supply, which has always been meager, cannot cope with so many more parched mouths.