It is a bold historian who writes a history of the Caucasus, as events of the past week have made all too clear. The region may not be much bigger than England and Wales, but its history involves three unrelated indigenous groups of people – the Abkhaz and Circassians in the north-west, the Chechens, Ingush and Dagestanis in the north-east, the Kartvelians (Georgians, Mingrelians and Svans) in the south – and representatives of many Eurasian groups (Iranian, Turkic, Armenian, Semitic, Russian) who have settled there over the past 2,000 years. Some forty mutually unintelligible languages, of which a handful are...