Historians can be a smug lot. They will never tire of telling you that decade- upsumming is just a retro-convenience; that any generalisations about its defining characteristics can be instantly undone by equally valid counter-generalisations. The 1950s? Tory complacency but also angry young men. The 1960s? Harold SuperMac and Harold GannexMac; mini and maxi; Quant and Biba. But the habit of imprinting a shape on the memory of a decade goes back in British historical writing at least to chronicles of the “Hungry Forties” of the 19th century: the years of Irish famine and Chartist riots. Bad times, especially, may have come in decimal blocks. No one called the next, more serene, decade (give or take a Crimean war or two) the “Fair Fifties”.

But this last 10-year span must have been the first to generate disagreement about what it should be called. Britain has opted for the “Noughties” but the US term is “Aughties” or “Oughties” as in “Christ, I oughta 've seen THIS coming!”

But no one did: not at the beginning or the end; and it is the bookending of the decade by two immense calamities – mayhem and meltdown; mass murder (for such we should call it, now that “9/11” has become a shorthand to bleach away the bloodstains) and mass unemployment – that makes it irresistible copy for decadal scribes. Tacitus himself could not have refrained from this particular morality play. Long ago, we were told by the French historians of the Annales School that spectacular events – the storming of the Bastille, the assassination at Sarajevo, and the decisions of individuals, be they Roosevelt or Hitler – were but spume on the crest of history's waves; that what really shaped the shoreline was the invisible pull of deep tides and currents far beneath the surface. Long-term influences are what change the world.