When is a genocide a genocide? The word is much in vogue, though its precise meaning – the intentional destruction of a people – is hard to justify in the case of Israel’s bombardment of Gaza, which, though without doubt brutal in execution and heartbreaking in effect, falls a long way short of any ambition to exterminate an entire population. Genocides don’t leaflet the populations they want to destroy with warnings to stay out of harm’s way, and Hamas, which Israel avowedly does want to see the back of, is not the Gazan people. For all the sensationalist pronouncements of...